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

Partnerships and Opportunities for Clean Cookstoves Support from Governments

This post aims to discuss where the opportunities may lie for governments and private sector organisations to enter partnerships for clean cookstoves market development. Both public and private sector actors have advantages and disadvantages in the approaches generally taken by such bodies in the clean cookstoves market space.

Map of stakeholders in the clean cookstoves sector in Ghana. Image: http://cleancookstoves.org/binary-data/RESOURCE/file/000/000/311-1.pdf

Public-sector operations have the ability to achieve scale quickly and effectively, however are often lacking in terms of lasting presences in markets due to the financing models (direct dissemination, direct subsidy) used most commonly in these circumstances. These models tend to lead to consumers failing to maintain use of disseminated equipment, leading to a shrinking of the market presence for cookstoves technologies in the longer term. Private sector market actors, conversely, can take longer to achieve scale in their operations, and have to contend with acquiring financing, either through their operations or donors, to continue maintaining their market presence.

Hence, there are significant, proven opportunities for the combination of approaches. Public-private partnerships (PPPs) have the potential to alleviate the negative aspects of both public and private approaches, with private sector actors operating as delivery agents for overarching public-sector objectives, or public sector operators supporting the development of a functioning private market.

The development and marketization of the Sri Lankan clean cookstoves sector, with donor agencies, the state electricity agency, and private sector companies all collaborating to develop a functioning private cookstoves market, is a good example of how PPPs can achieve successful results in the clean cookstoves market context. Support from the Ceylon Electricity Board (CEB) in distributing clean cookstoves to their existing customers allowed the development of functioning private production enterprises across the country, with a guaranteed market for their produce. Local production of clay stove liners is still continuing in the country. [1]

Steps in improving the enabling environment for clean cookstoves. [2]

The creation of an enabling environment for new businesses to enter the clean cookstoves market is another crucial role of governments in developing a clean cookstoves sector. The above image shows a number of pertinent steps that can be taken to do this. Starting at a consumer level, raising awareness of the benefits of a clean cookstove technology, through to allowing small and large businesses to access financing to scale their operations, and enabling credit facilities either through public or commercial banks, governments have the potential to significantly contribute to the ease of starting and maintaining a functioning private clean cookstoves market.

– Daniel Kerr, UCL Energy Institute

[1] Amerasekera, R.M. (2006) Commercialisation of improved cookstoves in Sri Lanka: A case study. Available at: http://www.inforse.org/Case/Case-SriLanka-Stoves.php3

[2] GVEP International (2012) Global Alliance for Clean Cookstoves Kenya Market Assessment, Sector Mapping. Available at: http://cleancookstoves.org/resources_files/kenya-market-assessment-mapping.pdf