Solar Water Heating as an Energy Service – Part 1 – Technology Choices and Markets

Solar water heaters as a product have the potential to contribute considerably to energy demand reduction in developing countries. This exists both as a household-scale technology, and in industrial applications such as desalination in countries such as the UAE and Saudi Arabia, and industrial process heat in both developed and developing countries. A number of developing countries around the world, notably those in Sub-Saharan Africa, have had success in disseminating solar water heating products on a commercial basis, in addition to a number of large-scale government dissemination programs. Countries such as South Africa (with around 500,000 systems installed as of 2016) and China (which has over 85 million installed SWH units as of 2016) have developed a robust network of commercial installers and manufacturers of solar water heating units and parts, selling products on a market basis to households and businesses.

Solar water heater installed by ESKOM, South Africa. Image: gmourits, Flickr, via http://inhabitat.com/eskom-installs-solar-powered-heaters-on-south-african-roofs/

 

There are a number of opportunities in developing country markets to develop a solar water heating sector. A number of developing countries, particularly those in Sub-Saharan Africa, have high levels of insolation (sunlight kWh/m2/day), and a consistent demand across income segments of the population for water heating. Industrial process heat is another sector where solar water heating could have an impact, as is institutional process heat, for example heat exchangers for hospital refrigeration, and hot water for use in health centres and schools.

Entrepreneurs and companies looking to enter the solar water heating market space need to consider a number of questions before starting their operations. Firstly, an appropriate technology choice is essential for succeeding in the SWH market, perhaps more so than many other renewable energy technologies. Deciding which consumer segment or income bracket to target informs the technology decision somewhat, but thorough research needs to be done on what the market and consumers can afford before deciding on a technology. Main technology streams for SWH include flat-plate solar collectors, and evacuated tube solar collectors. Both work on similar principles, heating water that passes through the collector, either through capillary action or through the use of an electric pump. Flat-plate collectors can be slightly less efficient than evacuated tube designs due to heat loss through convection, however they are also less expensive and simpler to produce. Evacuated tube designs are generally more efficient at heating water, but are also more expensive to compensate for the increased complexity in manufacture.

Flat-plate solar collector installed on a house in the United Kingdom. Image: uk.solarcontact.com

Flat-plate solar collector efficiency vs evacuated tube efficiency at various temperature ranges for a typical North American location. Source: https://blog.heatspring.com/solar-thermal-flat-plate-or-evacuated-tube-collectors/

 

When designing a new solar water heating business or intervention, therefore, it is important to consider which variant on the technology is to be used, and at what scale (household, institutional, industrial etc.), in order to plan dissemination based on affordability for the consumer. The next blog in this series will investigate business and financing models that can assist in improving the sustainability and replicability of solar water heating energy service companies.

– Daniel Kerr, UCL Energy Institute

References

Clean Technica (2015) World’s Largest Solar Powered, Jellyfish-Fightin’ Desalination Plant To Be Built in Saudi Arabia. Available at: https://cleantechnica.com/2015/01/22/worlds-largest-solar-powered-desalination-plant-under-way/

Urban, Geall & Wang (2016) Solar PV and solar water heaters in China: Different pathways to low carbon energy. Renewable and Sustainable Energy Reviews, Vol. 64, pp. 531 – 542

EE Publishers (2016) Solar water heater rollout programme gains momentum. Available at: http://www.ee.co.za/article/solar-water-heater-rollout-programme-gains-momentum.html

Solar Cooking and Energy Service Companies: An Unexplored Market Opportunity?

Solar cooking, as a technology and group of products, has existed for many decades, with examples being used in the 1970s. The technology in its simplest form has remained relatively unchanged since then, with the basic premise being either a flat or parabolic reflecting surface, placed in the sun, reflecting sunlight onto a cooking chamber. This can be either below the flat-plate reflector, or at the focal point of the parabolic collector. These types of devices are easy to manufacture and can be extremely cost-effective, with little more than a reflecting surface (for example, foil-backed card) and a cooking vessel needed for a minimum setup. These features give this technology particular applicability for targeting bottom-of-pyramid consumers with sustainability interventions: typical prices for simple designs (such as the flat-plate reflector shown below) range from US$3-5.

Solar box cooker made from carboard boxes and aluminium foil. Image: https://nakazora.files.wordpress.com/2011/06/solar-cooker1.jpg

Parabolic solar cooker in use at an informal settlement in Barcelona. Image: Brinerustle / Wikimedia Commons / CC BY-SA 3.0

 

A number of companies currently distribute simple kits for creating solar cookers from scratch, usually in the form of a reflective card template for the reflecting surface. However, these pre-packed kits are often more expensive than locally-sourcing materials for manufacture, ranging up to US$30-40, without offering meaningful benefits to the consumer aside from convenience. There are also a number of companies in developing countries that distribute full solar cookers to consumers using a direct-purchase business model, such as SunFire in South Africa and L’Obel Solar Power in India. Prices for these designs, commonly higher-quality parabolic mirror cookers, range up to US$200.

As such, it appears there is an opportunity for low-cost solar cooking business to develop markets for cheap, reliable solar cookers for bottom-of-pyramid consumers. In addition, through using alternative payment models for business, higher-cost designs can become more accessible to a greater number of consumers. Offering micro-credit products for deferred purchasing of solar cookers, or engaging with consumers on a fee-for-service basis with consumers paying a monthly fee for their product, would allow mid-range technologies to become accessible to consumers with lower incomes.

Other opportunities exist in the solar cooking market space for complimentary technologies, in particular heat-retention bags such as the Wonderbag from South Africa. This is designed to fit around the cooking vessel to retain heat and slow-cook the contents, after it has already been heated, reducing the overall energy requirement for cooking. Whilst this technology is perhaps most applicable to wood or charcoal-fired stoves, it can also help improve convenience when using solar cooking products. For example, rather than leaving a cooking vessel in the solar cooker for up to six hours, it can be left there for 1.5-2 hours, then transferred to the Wonderbag for further cooking.

For more information on the Wonderbag and use-case studies, please refer to https://samsetproject.wordpress.com/2017/04/10/energy-poverty-in-peri-urban-communities-in-polokwane-south-africa-part-1-identifying-the-issues/

— Daniel Kerr, UCL Energy Institute

References

Teach A Man To Fish (2009) Solar Cooker Business Guide. Available at: http://www.teachamantofish.org.uk/resources/incomegeneration/Solar-Cooker-Business-Guide.pdf

Gautam (2011) Microfinance Intervention for Financing Solar Cooking Technologies – Financing With Savings. Available at: http://www.microfinancegateway.org/sites/default/files/mfg-en-paper-microfinance-intervention-for-financing-solar-cooking-technologies-financing-with-savings-mar-2011.pdf

Solar Cookers International: CooKit. https://shop.solarcookers.org/?pn=CooKit&cn=Solar+Cookers&p=621&c=27

L’Obel Solar Power Systems: Solar Thermal Products: http://www.lobelpower.com/solar_thermal_product.htm

SunFire Solutions: http://www.sunfire.co.za/wp/

Wonderbag World: http://www.wonderbagworld.com/

Kitonyoni Solar Mini-grid and Integration of Thermal Energy Services

Binu Parthan from SEA writes on his recent visit to the Kitonyoni Solar Mini-Grid project, part of the University of Southampton’s efforts for the Energy for Development (E4D) project they lead.

The solar mini-grid at Kitonyoni near Machakos in Makueni County was financed by the UK government and commissioned in 2012 by the STEPs partner The Sustainable Energy Research Group at University of Southampton. The Kitonyoni Solar mini-grid is managed by Makueni County Solar Energy Co-op Society Ltd which is owned and managed by the community.

Management of the Solar Electric Cooperative and manager of the mini-grid business. Image: Sustainable Energy Associates

In July 2016, I travelled to Kitonyoni to visit the solar min-grid and meet with the community. While at Kitonyoni, I met with Joseph, Monicah, William and Shadrack from the management Makueni County Solar Energy Co-op Society Ltd and also with Stephen, the manager of the mini-grid and energy service business. With the community leaders and the manager of the mini-grid, I visited several businesses and households that were consuming electricity from the cooperative to understand the business model. The solar electric cooperative seems to be professionally managed and financially sustainable. They operate on a for-profit business basis and the financial accounts reveal that the operation is financially sustainable. The electricity cooperative uses a pre-paid card system for electricity sales and payments which seems to be working well. The electricity consumers are more conscious of energy use and payments and the cooperative is also happy with the upfront collections. The number of shops in the Kitonyoni market has significantly increased since the solar mini-grid was commissioned and the value of the land in the area has also almost tripled. However, the tariff charged by the solar electric cooperative is considerably higher than the public electricity utility but the community has been willing to pay a higher tariff due to better availability and reliability.

One of the new businesses established in the Kitonyoni market powered by the solar mini-grid. Image: Sustainable Energy Associates/span>

STEPs project team at University of Southampton had carried out a survey to examine the possibility of integrating thermal energy services into the existing electrical energy service business model. The results showed that 90% of the households in Kitonyoni use firewood for cooking which is available without cost to the community (Bahaj and Kanani, 2016). While the households spends over 5 hours to gather firewood, there is limited interest in switching to cleaner cooking options such as LPG which involve additional financial expenditure. The opportunity to integrate a solar thermal energy service along with the electricity service seems rather limited due to limited scope and demand for commercial fuels. The firewood is available freely in the area and LPG distribution networks are not available in the village.  Therefore currently, there does not seem to be a business case for introduction of an LPG franchise model and integrate the model into the solar electricity business. However some thoughts that I shared with the community were:

Since households and restaurants are cooking in separate rooms than their houses and as there is a preference for community schemes, will a community electric cooking scheme succeed? This may be relevant as on most days the battery bank of the solar mini-grid seems to be fully charged in the early afternoon and this could provide an opportunity for a central cluster of electric induction cookers which people can use to cook on a pay per use basis(similar to battery charging) to the cooperative.

It is possible that people may opt for efficient Cookstoves/Jikos if available on a hire-purchase/PAYG basis and reduce the amount of firewood to be collected resulting in time savings. An efficient Jiko will cost 45 $ which could be offered on a loan basis with daily/weekly/monthly payments to people by the cooperative for 6 months to 1 year tenure. These funds could be revolved over the time period to reach other members.

A differential tariff with a lower tier-tariff for the shops and establishments that use electricity during the day will likely improve the revenue model of the cooperative and can increase the utilisation levels. Such a tariff regime could allow the use of induction electric cookers at households during the day. Such a development could result in increasing sales and revenue and improving the business viability.

Cooking using firewood and a metallic stove in Kitonyoni. Image: Sustainable Energy Associates

Therefore the technology options for thermal energy and cooking in Kitonyoni is electric cooking or efficient Cookstoves with the possible business models of pay-per-use or hire-purchase respectively. A differential tariff with lower off-peak tariff could also allow electric cooking during the day time and improve the business model. These options are not entirely obvious and needs to be investigated and defined. This approach will certainly face stiff competition from free biomass availability and availability of free time for fire-wood collection.

Dr. Binu Parthan

The ‘Real 5P Model’ in Cinta Mekar

Binu Parthan from SEA writes on the implementation of a pro-poor public-private partnership (5P) model for micro-hydropower in Indonesia.

I first heard about the 5P model or the Pro-Poor-Public-Private-Partnership in 2012 when I was in the mountain kingdom of Lesotho. The UN’s Economic Commission for Africa were scoping for an energy centre to be run by a cooperative as a 5P model.  I found the idea of PPPs in rural energy that focused on poverty alleviation quite compelling in the context of the rural energy work I was doing at the time. This approach was reflected in the Lesotho Energy Alternatives Programme (LEAP) that I developed for UNDP and the Sustainable Thermal Energy Partnerships (STEPs) project that Xavier Lemaire of UCL Energy Institute and I developed with during 2012-2013. Fast forward 2 years and the STEPs project is generously funded by UK Aid and on its way, and while responding to the baseline study on the STEPs project, I hear from Hongpeng Liu and Deanna Morris at the Energy Division of UN’s Economic and Social Commission for Asia-Pacific (UN-ESCAP) about the original 5P model which has been working for over 10 years in Cinta Mekar, Indonesia.

With kind support from Tri Mumpuni of People Centred Business and Economic Institute (IBEKA) (who incidentally is a recipient of Magsaysay award for her work on hydro power for rural electrification), weeks later I find my way to Cinta Mekar, a relatively remote hilly village about 3 hours drive from Jakarta. The Cooperative at Cinta Mekar – Makar Sari is headed by a diminutive Yuyun Yunegsih, a grandmother of three who was elected a few years ago by the 450 members of the cooperative. The cooperative manages the 120 kW hydro power plant which was commissioned in 2003. The investment in the hydro-mechanical and electro-mechanical equipment and the building materials were financed 50:50 by UN-ESCAP and a private company Hidropiranti. The facilitation was by IBEKA and the members of the community and cooperatives contributed labour and local materials for civil construction in a normal PPP mode. Today after 12 years the hydro power system is still working well and generating and selling electricity to the local utility – PLN at slightly over US cents 4/kWh. 40% of the $650-$1100 monthly revenues go to Hydropiranti and 40% to Mekar Sari cooperative while 20% is set aside for maintenance, repairs and replacement.

The Mekar Sari cooperative has done a number of impressive ‘pro-poor’ initiatives over the years with its share of the revenues. It has provided financial assistance to households which could not afford to obtain an electricity connection. The cooperative also provides scholarships to 360 kids from the community, provides a land fund for members who do not have land holdings, provides an allowance for women in the community to cover childbirth related expenses and also pays an allowance to older members in the community. It has plans to construct public toilets, drinking water fountains etc. all of which seems very impressive. This is an impressive ‘pro-poor’ element that I have not seen in energy projects in general. I have seen impressive pro-poor energy initiatives driven by visionary and charismatic individuals but not by organisations for such a long duration and consistent track-record.

While the social development and pro-poor schemes have been very impressive, the business side has been slightly less impressive. The cooperative has not been successful in renegotiating in higher off-take tariffs in the power purchase agreement with PLN which pays almost a three times higher tariff for similar community hydro plants. A major investment in a manufacturing facility to make gluten-free banana flour which would have employed 10 people have not been successful and lies largely unutilised as the supply chain and market prospects were not investigated properly. It’s possible that the cooperative may have benefitted from some hard-nosed business advice. However the initiative can be considered a notable success in establishing a technical and management solution at an institutional level which has worked for over 12 years and has continued to be profitable and having driven social development in the community.

From the STEPs project perspective it was interesting to see that almost all the electrified community was using LP Gas or gathering wood from the forests for cooking, thus affirming our view that the thermal energy aspect is often overlooked and left to individual households to solve. What was interesting was also that many households which could afford were using electric rice cookers for cooking the main staple food, and efficient electric cooking is something STEPs hasn’t paid much attention. For the STEPs project plans, 5P model which combines private sector quality, efficiency and investments with public and community investment and participation, with community organisations managing social benefits and which combines both electricity and gas supply could indeed be a better model economically and socially. The question whether the institutionalised community leadership in Cinta Mekar can be replicated elsewhere remains. After my visit I asked Yuyun what the cooperatives biggest challenge was and contrary to what I expected it turned out to be the efforts by the local government to take over the cooperative. So while technical, economic and social challenges can be overcome in rural energy services, political challenges often pose a greater risk to sustainability.

– Binu Parthan, SEA

Yuyun Yunegsih at the Cinta Mekar 5P Hydro Power Plant. Image: Sustainable Energy Associates