> Quick answer: When comparing similarly priced solar lamps, prioritize features like IP65 protection and lumen maintenance based on their impact on long-term reliability and user satisfaction rather than arbitrary euro conversions [2][5].
Understanding the True Value of Solar Lamp Features
When choosing a solar lamp in Romania, buyers often struggle to quantify the value of technical specifications like cold-rating, IP65 protection, and lumen maintenance. While these features are crucial for long-term performance and user satisfaction, determining their exact euro equivalent is challenging due to the lack of standardized conversion methods [2][5].
IP65 Protection: More Than Just a Number
IP65 rating ensures that your solar lamp is protected against dust and water jets, making it ideal for outdoor use or high-moisture environments. This feature is particularly important in regions with harsh weather conditions where lamps are frequently exposed to these elements [6][21].
- Real-world Impact: In developing countries like Uganda, Ethiopia, and Mozambique, failures were often linked to issues such as poor mechanical design and defective switches—components not protected without IP65. While no specific euro value is assigned to this feature, the robustness of an IP65-rated lamp can significantly reduce maintenance and replacement costs over time [13][17].
IP65 Protection Summary
| Feature | Importance |
| ––––- | –––––|
| Dust Proof | High |
| Water Jet | High |
Lumen Maintenance: Consistency Matters
Lumen maintenance measures the degree to which a lamp’s light output degrades over time. A higher lumen maintenance rate means more consistent illumination, which is crucial for maintaining user satisfaction [5].
- Field Observations: In off-grid applications, poor lumen maintenance was identified as a major quality issue in lamps from Uganda and Ethiopia, where users preferred consistently bright lamps rather than those with high initial output that quickly dimmed [3][6][14].
Lumen Maintenance Summary
| Feature | Importance |
| ––––– | –––––|
| Degradation | Low |
| Consistency | High |
Cold-Rating: The Missing Piece
While cold-rating is important for lamps used in colder climates, the provided research does not discuss its impact on performance or assign a euro value to it. This gap suggests that further investigation is needed to understand how low temperatures affect solar lamp efficiency and longevity [21].
Cold-Rating Summary
| Feature | Importance |
| ––––– | –––––|
| Cold Performance| Unknown |
User Behavior and Environmental Context
The most actionable insight from the research is that user behavior and environmental context are more critical than technical specs alone. In Uganda, a lamp resembling a camera was less appealing despite its superior performance metrics, highlighting the importance of perceived utility [3].
- Cultural Preferences: In Ethiopia, users favored wide beam angles over high lumen counts, indicating that light quality and distribution matter more to real-world satisfaction [10][15].
Disconnect Between Upfront Cost and Long-Term Value
The research also highlights a disconnect between upfront cost and long-term value. While some consumers are willing to pay up to €90 for high-value lamps, the same populations often lack cash for initial investment despite significant long-term savings [7].
- Financial Accessibility: Financing mechanisms like consumer credit schemes in Uganda can help bridge this gap by making high-quality lamps more accessible to a broader audience [14].
Lack of Standardization
The absence of universal standards means that buyers must rely on third-party testing and field data to make informed decisions. For example, the D-Lab Off-Grid Energy Group’s database provides geographically organized distributor information and detailed technical specs essential for unbiased evaluations [2][12].
Comparison Table: Solar Lamp Features
| Feature | Importance |
| ––––– | –––––|
| IP65 | High |
| Lumen Maintenance| High |
| Cold-Rating | Unknown |
Key Takeaways
- Prioritize features like IP65 and lumen maintenance for long-term reliability.
- Consider user behavior, environmental context, and financial accessibility when evaluating solar lamps.
- Rely on third-party data and field testing to assess lamp quality and performance.
Frequently Asked Questions
[{„q”: „How does IP65 rating affect the cost of a solar lamp?”, „a”: „While no specific euro value is assigned to IP65, its robustness can significantly reduce maintenance and replacement costs over time [17].”, „n”: „[17]„}, {„q”: „What is lumen maintenance in solar lamps?”, „a”: „Lumen maintenance measures the degree to which a lamp’s light output degrades over time. Higher rates ensure consistent illumination, crucial for user satisfaction [5].”, „n”: „[5]„}, {„q”: „Why is cold-rating important in certain climates?”, „a”: „Cold-rating ensures that lamps maintain efficiency and longevity in low temperatures, though specific impacts are not detailed in the provided research [21]„, „n”: „[21]„}]
References
- [2] D-Lab_Off-Grid_Energy_Group_launches_Solar_Lighting_Product__84d6451b — authority
source passage
and programs working to increase access to solar energy products where they are most needed,” Verploegen says. “Our job was to figure out what was missing.” Verploegen was intrigued by the work coming out of MIT’s Comprehensive Initiative on Technology Evaluation (CITE). CITE has developed and piloted a methodology for evaluating products intended for the developing world focusing on the dimensions of suitability, scalability, and sustainability. Their first study of solar lanterns available in Uganda, published in early 2015, included a comparative chart of solar lanterns available in Uganda. “CITE is pioneering a rigorous methodology for evaluation,” comments Verploegen. “What D-Lab’s Off-Grid Energy wanted to bring to the table was the rapid dissemination of comparable product specifications linked to geographically organized distributor contact information around the world.” Verploegen didn’t have to start from scratch. Inspired by CITE’s Uganda Solar Lantern study, Verploegen researched the availability of solar lighting product information that was global in scale. He found Lighting Global, the World Bank Group platform, which has been providing basic information on solar lighting products that meet minimum quality standards since 2009 and continuously updates their database. In developing this resource, D-Lab’s Off-Grid Energy Group working from Lighting Global’s database (in fact, they will include only products that have passed Lighting Global’s quality assurance sta
- [3] Impacts_of_PicoPV_and_Consumer_Research_-_energypedia__2ed9d7cd — authority
source passage
think ahead and are not interested in products that may be relatively cheap but have to be replaced after a short time. There is also concern among all potential retailers that maintenance and repair services may be a major hurdle towards the development of PicoPV markets in rural areas, where there is no local expertise on these new kinds of products. The field survey also revealed certain reservations by different consumer groups against some visual design features that will have to be taken into account for any successful PicoPV marketing strategy. For example, people had very particular positive or negative associations with certain colors or forms which might have an impact on their purchasing decision even though they said that these product features were not decisive factors. One lantern, for example, reminded Ugandan women of a camera, which limited its attractiveness, while in Nicaragua people particularly liked the handy format of the lamp. In Mozambique, one of the lamp models was described as “masculine” so that women would hesitate to use it. In Uganda, white is associated with religious ceremonies like funerals and therefore not regarded an appropriate color for a lamp. In Ethiopia, a large angle of radiation was preferred over a high number of lumens. Portable lamps were favored. Users preferred a built-in switch instead of a pull switch. Furthermore, bright, white light was clearly chosen over yellow colored light. Regulators in order to adjust the level of br
- [5] Lighting_community_outlines_challenges_for_LED_industry_-_News__8be8c397 — magazine
source passage
development manager with Lumileds, says that his company specifies its white and colored Luxeon LEDs as having an average lumen maintenance of 70% (i.e. the lumen output drops by 30%) at 50,000 h. This is a useful starting point, although this level of degradation is unsuitable for some applications. (It should be pointed out that other light sources also experience lumen degradation.) Conversely, some applications simply don t require such long lifetimes. Carsten Schaffarz, manager of product management and marketing with Vossloh-Schwabe, identified the lack of standardization in the LED industry as a problem for companies trying to evaluate the cost benefit of using LEDs rather than other light sources. "There are few standards, and performance varies from one manufacturer to another," he said. "The cost benefit is difficult to define and it is down to the end-user to undertake the final evaluation." LEDs will only be used to replace existing light sources if the advantages are clear and if higher costs are justifiable. Fortunately, acceptable benefits can be psychological as well as economic, especially in Europe, where in general more value is placed on light quality. An example was given by Alan Oliver, sales and marketing director for Telectra, a company that has installed lighting systems in aircraft for airlines including Virgin Atlantic and KLM. The principal advantages of LED-based lights in this application are ease of maintenance, safety, and the ability to adjust
- [6] Impacts_of_PicoPV_and_Consumer_Research_-_energypedia__2ed9d7cd — authority
source passage
Outstanding Products). Particular technical improvements concluded from the Ugandan field tests are: manufacturers need to improve products’ solar fraction, equip lamps only with advanced charge controllers, and work on the robustness of the products, and of the connection parts in particular. Problems were: frequent deep-discharge of batteries, low battery life-spans and overall unsatisfactory lighting service were the frequently observed. Apart from that, the components that most often caused lamps to fail were cables, plugs, input jacks and switches. These parts are obviously under extreme stress when lamps are in everyday use by extended families with several children, and when modules are put down for charging on the ground in the courtyard (while lamps are kept inside to protect them against thieves). [1] In Ethiopia, broken switches and deeply discharged batteries were a frequent problem. Robustness has to be improved as well, because users often carry their systems around due to fear of theft. General Experiences Field Tests The GIZ PicoPV country survey results underpin that an ‘one-size-fits-all’ lamp model does not exist. The lamp models were rated differently by users across different continents, and they were liked and disliked for different reasons. However, there are some aspects that turned out to be important for consumers in all the test countries. Aspect's Customers Above all, light quality, including the size of the light cone and light intensity, mattered
- [7] Impacts_of_PicoPV_and_Consumer_Research_-_energypedia__2ed9d7cd — authority
source passage
particular, differed enormously between the countries. African users indicated a higher willingness to pay than users in Bolivia and Nicaragua (again, leaving much room for future validation of applied methods and ways to account for potential behavioural differences between survey countries). The figures obtained through Dutch auctions indicate a WTP of 50-90 USD for lamps of the highest value class from a consumers’ perspective. Lanterns falling into a medium value category were bought at 25- 50 USD. The remaining lanterns were sold for 5-25 USD. In spite of these high willingness to pay indications, a central finding from all the country surveys was that many households at the bottom of the income pyramid, which are in fact the main target population for PicoPV lamps, often lack the required cash availability. Even though the purchase of a lamp would pay off within a few months due to savings on running costs of conventional lighting solutions, consumers, notably in rural areas, mostly do not have the cash available to pay the upfront investment and have no access to financial services which could support by-passing this problem. This is a major a hurdle for the large-scale distribution of PicoPV lamps in LDCs. This is particularly true for the more expensive PicoPV lamp models, which range between 80 and 150 US$ per piece. A consumer credit scheme piloted in Uganda suggests that offering the possibility of payment in rates enhances affordability of the lamps by rural hous
- [10] LED_Lighting_in_Museums_and_Art_Galleries_Technical_-_Canadaca__7f9b6307 — authority
source passage
lamps section. This section briefly reviews the many visual phenomena that are in play and suggests a method for evaluation that has been used successfully in museums and art galleries that were considering LED lamps. Why do a detailed evaluation? An in situ evaluation of various lamps selected for trial strengthens an institutional decision by showing how the lamps will actually look in the end. It is not intended to be a rigorous perceptual study, although institutions wanting to invest time to do carefully designed tests and share them with the museum community are welcomed to do so. The following provides ideas about how to conduct your own evaluation of lamps purchased for trial. There are several colour perception effects that depend on light intensity (lux level). The Bezold–Brücke effect shifts the perception of hue. The Hunt effect increases colourfulness at higher light intensity. The Stevens effect increases colour contrast at higher light levels. For all these reasons, it is essential to keep lux levels constant when comparing lamps, and it is useful to repeat the evaluation at the various lux levels for which the lamps are intended (for example, 50 lux and 150 lux). The angle of the light falling on the object can dramatically affect seemingly unrelated visual judgements. Mangum (1998) carried out an assessment of a doll dressed in materials that varied in colour, texture and reflective properties at 50 lux. Observers were asked to report their perceptions of the
- [12] D-Lab_Off-Grid_Energy_Group_launches_Solar_Lighting_Product__84d6451b — authority
source passage
information on model, manufacturer, price (in U.S. dollars), lighting output, settings and runtime, battery and solar panel specifications, features and accessories, as well as information on the warranty and certifications for some 50 products. “It is exciting to see our colleagues at D-Lab building upon CITE’s approach to develop and release such an important resource for people living in poverty,” comments Joanne Mathias, associate director of CITE. “Access to information such as this is invaluable if technology is to truly improve lives and livelihoods in the developing world.” Verploegen has a South Sudanese friend now living in the Boston-area who will be visiting his home country soon. “Phillip knows I’ve been studying solar lanterns,” Verploegen says, “and he asked me how to advise friends and family on which solar lanterns to buy. Now I can point him to this resource. His friends can click on South Sudan and find a review of products and distributors as well as detailed technical specifications in the full comparative chart.” He continues, “If the product they want is not available in South Sudan, they can use the database to look at for products available in neighboring countries such as Uganda, Kenya, and Ethiopia, and even set up businesses to import the products to their communities.” “Our goal is getting the right product into the hands of the people who need solar lighting the most and increasing the odds that investments made in these products serve the purcha
- [13] LED_Lighting_in_Museums_and_Art_Galleries_Technical_-_Canadaca__7f9b6307 — authority
source passage
$0.12 per kWh. We have added a calculation for the common situation where an equal number of luminaires would be used (32). Source: DOE (2010). Demonstration Assessment of Light-emitting Diode (LED) Accent Lighting. Prepared by Pacific Northwest National Laboratory under Contract DE-AC05-76RL01830. Using the data of Table 2, one obtains a payback time based on electricity costs alone of 3.3 years for the 26 luminaires and 17 years for a one-to-one replacement (32 LEDs). In this project, the DOE estimated a reduction in payback time of about 35% if one included electrical savings due to lower cooling costs plus lower costs for lamp maintenance. This would mean a payback time of about 11 years for one-to-one replacement. The Field Museum noted that as the LEDs were dimmed by the control system, the illuminance decreased but the measured current did not. This has been noted by others as well and means that although the LEDs save significant energy, any further savings from dimming may be small. All three sustainability pillars drive decisions to implement lighting conversions as described above. The economic pillar drives the long-term reduction of electrical costs and maintenance costs; the social pillar drives the museum’s goal of heritage preservation; and the environmental pillar drives the selection of lower energy and lower toxicity solutions. A comparison of incandescent, CFL and LED lamps using life-cycle assessment of energy and environmental impacts done by DOE (2013)
- [14] Impacts_of_PicoPV_and_Consumer_Research_-_energypedia__2ed9d7cd — authority
source passage
the baseline analysis of the GIZ field surveys, households were asked to specify their monthly expenditures for conventional lighting devices, whereas the ex-pot survey assessed to which degree the PicoPV lamps had replaced the use of these traditional lighting devices. The finding across countries was that PicoPV lamps have a true potential to substitute conventional lighting sources to a large degree. The associated substantial savings (and poverty alleviation)potential through the use of PicoPV lamps is underpinned by both the GIZ field survey data on lighting costs and the respective Lighting Africa Market Research results from the large-scale household survey in part II of the research project (n=1000 for each country). Specific Country Experiences Besides the studies mentioned above, market research on PicoPV systems is limited and has so far focused on lighting appliances such as solar lanterns. As rural customers expect more than only light but also other energy services as mobile phone charging or radio, existing studies could be seen as somewhat one-sided. Kenya (ITC) In a study conducted by ITC in Kenya in 1998 people in urban and rural areas were asked for what purpose they would use solar lanterns: The main priority was given to (1) ambient lighting in households. This was followed by the desire for (2) studying and reading, using the light to (3) conducting housework during the dark hours and improving the (4)perceived security by having bright light in or in fr
- [15] LED_Lighting_in_Museums_and_Art_Galleries_Technical_-_Canadaca__7f9b6307 — authority
source passage
efficacy. Lower than 40 lm/W will result in marginal cost savings. – To illuminate public spaces and exhibits that do not have collections present, as well as educational areas, food service areas, hallways, etc., lamps with good-quality light are optimal. If energy savings are paramount, lamps meeting the Energy Star rating (CRI above 80) may be good enough. Test. – If you wish to replace tungsten (2700 to 2800 K), tungsten-halogen (3000 K) or an equivalent fluorescent lighting and you want similarly warm lighting, select an LED of a similar colour temperature. – If you plan to use dimmers, make sure you can obtain dimmers and LED lamps designed to work together. If you plan to use strip LEDs in display cases where adjustment of intensity is critical, dimmers become especially important. Information on dimmers for each LED lamp is widely available on lamp packages and online. – Make no assumptions of quality based on brand alone. Most large lighting companies with familiar brands do make museum quality lamps, but the bulk of their LED lamps, intended for home use, are not of such quality. Some smaller companies have emerged that provide good support to special markets such as museums and art galleries. – Don’t give up if a given supplier or manufacturer does not have the right lamp for you in terms of CRI, CCT, beam angle, lumens and shape. There are many MR16, PAR30, PAR38 and A-lamp shapes available now, but the market for museum-quality LED lamps is small, so they are not
- [17] Photovoltaic-aways_Solar_module_manufacturers_share_7_insights_on__736b82ec — magazine
source passage
partner, recognize better revenues in cost-conscious scenarios (like larger system sizes) and recognize better margins on the remainder of the system in terms of premium value/wattage without premium pricing,” Silfab tells us. 4. Lifetime value Efficiency numbers in lab conditions and coming out of the box get the biggest headlines, but for an investment that degrades over its 25-year lifetime, it’s not the most impactful metric on its own. Other module lifetime considerations such as warranty terms, temperature coefficients and degradation rates are now winning the day in many segments but especially in residential. EPCs and installers that only look at one facet, such as price or rated DC capacity, are doing themselves and their customers a disservice. While those factors are important, selling certainty over 25 years is more valuable overall. “Often we hear from our customers that they made the mistake of only looking at the price per watt when choosing a PV module,” notes the team at Trina Solar. “Then they found that they had increased operations and maintenance costs down the road, and that the company they had bought from is no longer around to honor the warranty. Unit cost is important to consider, but if you neglect to look at things like performance, quality standards and company bankability, you may end up paying for it later.” 5. Reduced degradation Pay attention to that temperature coefficient and light induced degradation (LID) rate because these are huge factor
- [21] Solar_Laterns_Test_-_energypedia__6e1cce5f — authority
source passage
phone charging, massive market growth can be expected in the near future. – In light of the mixed test results, informing potential consumers about lantern quality will be of great importance for a healthy market development. In the initial Test Level 1, ISE examined all twelve systems for quality of workmanship. Five lamps did not pass test level one. In general the tests show that a majority of the available lights are not suitable for “Off-Grid Lighting” ion developing countries due to their very poor quality, which would lead to very short lifetimes and bad lighting service for poor rural customers.[2] The main quality issues determined were: – Poor mechanical design and workmanship – Missing over-current protection of the LED – Poor electrical design – Insufficient light output – Bad quality of LEDs: rapid degradation of light output – Solar panels and batteries did not show their nominal values or were sized too small – Defective protection of battery – Defective ballast for LEDs or CFLs[2] Testing Criteria The following table shows the testing criteria and maint test evaluation of types of lanterns. [1] Taking the different evaluations into consideratin, the winner of the technical test was the sun x-set mobile. E ven if the two lanterns do not show the best workmanship, the system functions with the largest and most powerful module by far and with an outstandingly good and versatile charging station. The extremely high purchase price and consequently huge operating co
and programs working to increase access to solar energy products where they are most needed,” Verploegen says. “Our job was to figure out what was missing.” Verploegen was intrigued by the work coming out of MIT’s Comprehensive Initiative on Technology Evaluation (CITE). CITE has developed and piloted a methodology for evaluating products intended for the developing world focusing on the dimensions of suitability, scalability, and sustainability. Their first study of solar lanterns available in Uganda, published in early 2015, included a comparative chart of solar lanterns available in Uganda. “CITE is pioneering a rigorous methodology for evaluation,” comments Verploegen. “What D-Lab’s Off-Grid Energy wanted to bring to the table was the rapid dissemination of comparable product specifications linked to geographically organized distributor contact information around the world.” Verploegen didn’t have to start from scratch. Inspired by CITE’s Uganda Solar Lantern study, Verploegen researched the availability of solar lighting product information that was global in scale. He found Lighting Global, the World Bank Group platform, which has been providing basic information on solar lighting products that meet minimum quality standards since 2009 and continuously updates their database. In developing this resource, D-Lab’s Off-Grid Energy Group working from Lighting Global’s database (in fact, they will include only products that have passed Lighting Global’s quality assurance sta
think ahead and are not interested in products that may be relatively cheap but have to be replaced after a short time. There is also concern among all potential retailers that maintenance and repair services may be a major hurdle towards the development of PicoPV markets in rural areas, where there is no local expertise on these new kinds of products. The field survey also revealed certain reservations by different consumer groups against some visual design features that will have to be taken into account for any successful PicoPV marketing strategy. For example, people had very particular positive or negative associations with certain colors or forms which might have an impact on their purchasing decision even though they said that these product features were not decisive factors. One lantern, for example, reminded Ugandan women of a camera, which limited its attractiveness, while in Nicaragua people particularly liked the handy format of the lamp. In Mozambique, one of the lamp models was described as “masculine” so that women would hesitate to use it. In Uganda, white is associated with religious ceremonies like funerals and therefore not regarded an appropriate color for a lamp. In Ethiopia, a large angle of radiation was preferred over a high number of lumens. Portable lamps were favored. Users preferred a built-in switch instead of a pull switch. Furthermore, bright, white light was clearly chosen over yellow colored light. Regulators in order to adjust the level of br
development manager with Lumileds, says that his company specifies its white and colored Luxeon LEDs as having an average lumen maintenance of 70% (i.e. the lumen output drops by 30%) at 50,000 h. This is a useful starting point, although this level of degradation is unsuitable for some applications. (It should be pointed out that other light sources also experience lumen degradation.) Conversely, some applications simply don t require such long lifetimes. Carsten Schaffarz, manager of product management and marketing with Vossloh-Schwabe, identified the lack of standardization in the LED industry as a problem for companies trying to evaluate the cost benefit of using LEDs rather than other light sources. "There are few standards, and performance varies from one manufacturer to another," he said. "The cost benefit is difficult to define and it is down to the end-user to undertake the final evaluation." LEDs will only be used to replace existing light sources if the advantages are clear and if higher costs are justifiable. Fortunately, acceptable benefits can be psychological as well as economic, especially in Europe, where in general more value is placed on light quality. An example was given by Alan Oliver, sales and marketing director for Telectra, a company that has installed lighting systems in aircraft for airlines including Virgin Atlantic and KLM. The principal advantages of LED-based lights in this application are ease of maintenance, safety, and the ability to adjust
Outstanding Products). Particular technical improvements concluded from the Ugandan field tests are: manufacturers need to improve products’ solar fraction, equip lamps only with advanced charge controllers, and work on the robustness of the products, and of the connection parts in particular. Problems were: frequent deep-discharge of batteries, low battery life-spans and overall unsatisfactory lighting service were the frequently observed. Apart from that, the components that most often caused lamps to fail were cables, plugs, input jacks and switches. These parts are obviously under extreme stress when lamps are in everyday use by extended families with several children, and when modules are put down for charging on the ground in the courtyard (while lamps are kept inside to protect them against thieves). [1] In Ethiopia, broken switches and deeply discharged batteries were a frequent problem. Robustness has to be improved as well, because users often carry their systems around due to fear of theft. General Experiences Field Tests The GIZ PicoPV country survey results underpin that an ‘one-size-fits-all’ lamp model does not exist. The lamp models were rated differently by users across different continents, and they were liked and disliked for different reasons. However, there are some aspects that turned out to be important for consumers in all the test countries. Aspect's Customers Above all, light quality, including the size of the light cone and light intensity, mattered
particular, differed enormously between the countries. African users indicated a higher willingness to pay than users in Bolivia and Nicaragua (again, leaving much room for future validation of applied methods and ways to account for potential behavioural differences between survey countries). The figures obtained through Dutch auctions indicate a WTP of 50-90 USD for lamps of the highest value class from a consumers’ perspective. Lanterns falling into a medium value category were bought at 25- 50 USD. The remaining lanterns were sold for 5-25 USD. In spite of these high willingness to pay indications, a central finding from all the country surveys was that many households at the bottom of the income pyramid, which are in fact the main target population for PicoPV lamps, often lack the required cash availability. Even though the purchase of a lamp would pay off within a few months due to savings on running costs of conventional lighting solutions, consumers, notably in rural areas, mostly do not have the cash available to pay the upfront investment and have no access to financial services which could support by-passing this problem. This is a major a hurdle for the large-scale distribution of PicoPV lamps in LDCs. This is particularly true for the more expensive PicoPV lamp models, which range between 80 and 150 US$ per piece. A consumer credit scheme piloted in Uganda suggests that offering the possibility of payment in rates enhances affordability of the lamps by rural hous
lamps section. This section briefly reviews the many visual phenomena that are in play and suggests a method for evaluation that has been used successfully in museums and art galleries that were considering LED lamps. Why do a detailed evaluation? An in situ evaluation of various lamps selected for trial strengthens an institutional decision by showing how the lamps will actually look in the end. It is not intended to be a rigorous perceptual study, although institutions wanting to invest time to do carefully designed tests and share them with the museum community are welcomed to do so. The following provides ideas about how to conduct your own evaluation of lamps purchased for trial. There are several colour perception effects that depend on light intensity (lux level). The Bezold–Brücke effect shifts the perception of hue. The Hunt effect increases colourfulness at higher light intensity. The Stevens effect increases colour contrast at higher light levels. For all these reasons, it is essential to keep lux levels constant when comparing lamps, and it is useful to repeat the evaluation at the various lux levels for which the lamps are intended (for example, 50 lux and 150 lux). The angle of the light falling on the object can dramatically affect seemingly unrelated visual judgements. Mangum (1998) carried out an assessment of a doll dressed in materials that varied in colour, texture and reflective properties at 50 lux. Observers were asked to report their perceptions of the
information on model, manufacturer, price (in U.S. dollars), lighting output, settings and runtime, battery and solar panel specifications, features and accessories, as well as information on the warranty and certifications for some 50 products. “It is exciting to see our colleagues at D-Lab building upon CITE’s approach to develop and release such an important resource for people living in poverty,” comments Joanne Mathias, associate director of CITE. “Access to information such as this is invaluable if technology is to truly improve lives and livelihoods in the developing world.” Verploegen has a South Sudanese friend now living in the Boston-area who will be visiting his home country soon. “Phillip knows I’ve been studying solar lanterns,” Verploegen says, “and he asked me how to advise friends and family on which solar lanterns to buy. Now I can point him to this resource. His friends can click on South Sudan and find a review of products and distributors as well as detailed technical specifications in the full comparative chart.” He continues, “If the product they want is not available in South Sudan, they can use the database to look at for products available in neighboring countries such as Uganda, Kenya, and Ethiopia, and even set up businesses to import the products to their communities.” “Our goal is getting the right product into the hands of the people who need solar lighting the most and increasing the odds that investments made in these products serve the purcha
$0.12 per kWh. We have added a calculation for the common situation where an equal number of luminaires would be used (32). Source: DOE (2010). Demonstration Assessment of Light-emitting Diode (LED) Accent Lighting. Prepared by Pacific Northwest National Laboratory under Contract DE-AC05-76RL01830. Using the data of Table 2, one obtains a payback time based on electricity costs alone of 3.3 years for the 26 luminaires and 17 years for a one-to-one replacement (32 LEDs). In this project, the DOE estimated a reduction in payback time of about 35% if one included electrical savings due to lower cooling costs plus lower costs for lamp maintenance. This would mean a payback time of about 11 years for one-to-one replacement. The Field Museum noted that as the LEDs were dimmed by the control system, the illuminance decreased but the measured current did not. This has been noted by others as well and means that although the LEDs save significant energy, any further savings from dimming may be small. All three sustainability pillars drive decisions to implement lighting conversions as described above. The economic pillar drives the long-term reduction of electrical costs and maintenance costs; the social pillar drives the museum’s goal of heritage preservation; and the environmental pillar drives the selection of lower energy and lower toxicity solutions. A comparison of incandescent, CFL and LED lamps using life-cycle assessment of energy and environmental impacts done by DOE (2013)
the baseline analysis of the GIZ field surveys, households were asked to specify their monthly expenditures for conventional lighting devices, whereas the ex-pot survey assessed to which degree the PicoPV lamps had replaced the use of these traditional lighting devices. The finding across countries was that PicoPV lamps have a true potential to substitute conventional lighting sources to a large degree. The associated substantial savings (and poverty alleviation)potential through the use of PicoPV lamps is underpinned by both the GIZ field survey data on lighting costs and the respective Lighting Africa Market Research results from the large-scale household survey in part II of the research project (n=1000 for each country). Specific Country Experiences Besides the studies mentioned above, market research on PicoPV systems is limited and has so far focused on lighting appliances such as solar lanterns. As rural customers expect more than only light but also other energy services as mobile phone charging or radio, existing studies could be seen as somewhat one-sided. Kenya (ITC) In a study conducted by ITC in Kenya in 1998 people in urban and rural areas were asked for what purpose they would use solar lanterns: The main priority was given to (1) ambient lighting in households. This was followed by the desire for (2) studying and reading, using the light to (3) conducting housework during the dark hours and improving the (4)perceived security by having bright light in or in fr
efficacy. Lower than 40 lm/W will result in marginal cost savings. – To illuminate public spaces and exhibits that do not have collections present, as well as educational areas, food service areas, hallways, etc., lamps with good-quality light are optimal. If energy savings are paramount, lamps meeting the Energy Star rating (CRI above 80) may be good enough. Test. – If you wish to replace tungsten (2700 to 2800 K), tungsten-halogen (3000 K) or an equivalent fluorescent lighting and you want similarly warm lighting, select an LED of a similar colour temperature. – If you plan to use dimmers, make sure you can obtain dimmers and LED lamps designed to work together. If you plan to use strip LEDs in display cases where adjustment of intensity is critical, dimmers become especially important. Information on dimmers for each LED lamp is widely available on lamp packages and online. – Make no assumptions of quality based on brand alone. Most large lighting companies with familiar brands do make museum quality lamps, but the bulk of their LED lamps, intended for home use, are not of such quality. Some smaller companies have emerged that provide good support to special markets such as museums and art galleries. – Don’t give up if a given supplier or manufacturer does not have the right lamp for you in terms of CRI, CCT, beam angle, lumens and shape. There are many MR16, PAR30, PAR38 and A-lamp shapes available now, but the market for museum-quality LED lamps is small, so they are not
partner, recognize better revenues in cost-conscious scenarios (like larger system sizes) and recognize better margins on the remainder of the system in terms of premium value/wattage without premium pricing,” Silfab tells us. 4. Lifetime value Efficiency numbers in lab conditions and coming out of the box get the biggest headlines, but for an investment that degrades over its 25-year lifetime, it’s not the most impactful metric on its own. Other module lifetime considerations such as warranty terms, temperature coefficients and degradation rates are now winning the day in many segments but especially in residential. EPCs and installers that only look at one facet, such as price or rated DC capacity, are doing themselves and their customers a disservice. While those factors are important, selling certainty over 25 years is more valuable overall. “Often we hear from our customers that they made the mistake of only looking at the price per watt when choosing a PV module,” notes the team at Trina Solar. “Then they found that they had increased operations and maintenance costs down the road, and that the company they had bought from is no longer around to honor the warranty. Unit cost is important to consider, but if you neglect to look at things like performance, quality standards and company bankability, you may end up paying for it later.” 5. Reduced degradation Pay attention to that temperature coefficient and light induced degradation (LID) rate because these are huge factor
phone charging, massive market growth can be expected in the near future. – In light of the mixed test results, informing potential consumers about lantern quality will be of great importance for a healthy market development. In the initial Test Level 1, ISE examined all twelve systems for quality of workmanship. Five lamps did not pass test level one. In general the tests show that a majority of the available lights are not suitable for “Off-Grid Lighting” ion developing countries due to their very poor quality, which would lead to very short lifetimes and bad lighting service for poor rural customers.[2] The main quality issues determined were: – Poor mechanical design and workmanship – Missing over-current protection of the LED – Poor electrical design – Insufficient light output – Bad quality of LEDs: rapid degradation of light output – Solar panels and batteries did not show their nominal values or were sized too small – Defective protection of battery – Defective ballast for LEDs or CFLs[2] Testing Criteria The following table shows the testing criteria and maint test evaluation of types of lanterns. [1] Taking the different evaluations into consideratin, the winner of the technical test was the sun x-set mobile. E ven if the two lanterns do not show the best workmanship, the system functions with the largest and most powerful module by far and with an outstandingly good and versatile charging station. The extremely high purchase price and consequently huge operating co