Distributed Renewable Energy Technologies

People in rural and remote regions are acquiring improved access to energy in three ways: (1) at the household level, using isolated devices and systems for power generation, heating, and cooking; (2) through community-level mini-grid systems; and (3) through grid-based electrification, where the grid is extended beyond urban areas.10 This section focuses on the first two (distributed) means of improving energy access. (See Sidebar 9.)

The installation and use of distributed renewable energy technologies in remote and rural areas for electricity, cooking, heating and cooling increased during 2013. This expansion was a direct result of improved affordability, greater access to financing, greater knowledge about local resources, and more-advanced technologies that can be tailored to meet customers' specific needs.

The dramatic price reductions of the past few years have rendered solar PV more affordable, even for very small-scale applications. The popularity of solar lanterns, solar-pico PV systems (SPS) (1-10 W capacity), and slightly larger solar home systems (SHS) (10-200 W), continued to rise in 2013. SPS can be easily self-installed and are now commonly available for providing basic services such as lighting, communications, and battery or mobile phone charging. The availability of end-user appliances that can be powered by SHS continues to expand, raising interest in these systems in rural areas. One of the most successful SHS programmes has been carried out in Bangladesh, where more than 2 million systems were installed as of May 2013.11

Small-scale wind turbines (up to 50 kW) have experienced performance improvements due to the emergence of advanced materials and wireless technologies in recent years. During 2013, small-scale wind turbines were being used predominantly for battery charging, telecommunications, irrigation, and water pumping, where the variable nature of their generation can be managed easily.12

One of the most successful programmes promoting the deployment of small-scale, decentralised wind turbines is in Inner Mongolia, China. In this area around 130,000 systems, each 200-1,000 W, were in operation as of early 2013, providing electricity to more than 500,000 people. The programme's success has been attributed to the stability of the institutional frameworks over the last two decades.13

Micro- and pico-hydro stations as small as 1 kW are common in many countries, providing local communities with affordable electricity.14 Typically, such hydro systems operate reliably for at least 20 years and require minimal maintenance (other than keeping the intake screen free of debris). Nepal had more than 2,500 micro- and pico-hydro systems installed by the end of 2012, with a total capacity of 20 MW.15 In addition, several 1 kW systems have been installed in southern India, mostly by private parties and without government support.16

To fuel engine-powered generators in a rising number of countries, vegetable oils from coconut, jatropha, and other sources are being used to displace diesel. In Thailand, biodiesel for electricity generation is being produced on a small scale from used cooking oil.17 In India, Vietnam, and elsewhere, biogas produced from dry wood, weeds, and rice husks is used increasingly to fuel engines, driving generator sets to supply electricity to mini-grids.18

Mini-grids are becoming increasingly prevalent around the world.19 Their technical evolution in the last fewyears, including the use of modular technology to integrate renewables, has led to a scaling up of renewables powered mini-grids. In addition, advances in information and communication technology applications for power management and end-user services are improving meteringand billing, load management, and remote diagnostics.20 As part of India's programme to increase access to electricity, over 80 villages had operating mini-grids using gasifiers and locally available biomass residues (including mustard stems, corn cobs, and grasses procured from local farmers) by mid-2013.21

The rural heating and cooling sector has progressed due to advances in technology, as well as to the increasing popularity of programmes educating rural populations about the benefits of using modern biomass and solar thermal systems for clean cooking, and water and space heating.22 The Africa Clean Cooking Energy Solutions Initiative was established to promote enterprise-based large-scale dissemination and adoption of clean cooking solutions in sub-Saharan Africa. The phased implementation of this programme began in 2013 in consultation with over 130 stakeholders from 26 African countries.23 To date, however, there have been very few successful cases of international, large-scale deployment of improved cookstoves.24

Clean cookstove designs are tremendously diverse, and new ones are still emerging. Some models use alternative clean fuels, whereas other advanced stove designs rely on traditional biomass but increase the efficiency of the combustion process, thereby reducing the amount of fuel consumed to provide the same amount of heat. Biomass cookstove designs that can achieve high levels of performance include forced air and gasifier stoves, which lower emissions significantly and reduce fuel use by 40-60% relative to an open fire.25 Such efficient biomass cookstoves are being sold for as little as USD 5-25 each.26

These advanced cookstoves rely primarily on the use of traditional biomass from forest fuelwood, crop residues, and animal dung. A wide variety of other fuels are also being used for household cooking purposes (although at a far smaller scale). These include ethanol, biogas, wood pellets, and solar energy, as well as non-renewable fuels such as coal, kerosene, and liquefied petroleum gas (LPG).27

Simple anaerobic digester technology can produce clean biogas fuel for cooking from animal manure, crop residues, and other organic waste feedstocks. These biogas systems perform better in warmer climates, but they can function under a variety of conditions, and their numbers continue to increase. Biogas is best suited for the estimated 155 million households and commercial farms where sufficient animal manure (and human waste) can be collected on a daily basis.28 Widespread acceptance and dissemination of biogas technologies have yet to materialise in many countries, due mainly to the high capital cost, which makes even small-scale units unaffordable for poor households.29

However, domestic-scale biogas installations have surged in some countries in recent years, driven by a number of international programmes.30 In 2013, China added 1.8 million units to bring the total to more than 43.5 million, thereby remaining the leader in the use of small-scale biogas plants.31 India constructed about 125,000 units during 2012, bringing the total to nearly 4.7 million by early 2013.32 By the middle of 2013, Nepal had more than 290,500 biogas plants in use, due at least in part to a multi-year government consumer subsidy, and Kenya had more than 9,000 units in place.33

Under suitable circumstances, solar thermal cookers can save time, work, money, and the need for combustible fuels. A large numberofsolarcookers have been deployed in Nepal, especially in refugee camps and small villages in the Himalayas.34 However, solar cookers, once considered a popular choice, are now on a waning trend.35 The cookers are unfamiliar to those accustomed to preparing food over an open flame, often after the heat of the day has passed, so adaptation to these stoves requires training and follow-up.36

The same is true for other cooking technologies. The transition of advanced cookstoves from the laboratory to households is not an easy task. Awareness-raising, targeted product trials, demonstrations, and feasible financing mechanisms are often all required to encourage people to move away from their traditional cooking methods. Improved cookstoves that are designed to operate similarly to traditional stoves have been accepted culturally by many developing country households. However, they continue to face severe market challenges in communities with relatively easy access to traditional biomass fuels.37 In cold climates, cookstoves are also often used to provide space heating, which can influence the choice of stove design and fuel.

10 IFC, From Gap to Opportunity: Business Models for Scaling Up Energy Access (Washington, DC: 2012), Executive Summary, http://www.ifc.org/wps/wcm/connect/b7ce4c804b5dl0c58d90cfbbd578891b/ExecutiveSummary.pdf?MOD=AJPERES.

11 Her Excellency Sheikh Hasina, Prime Minister, Government of the People's Republic of Bangladesh, "2 Million Solar Home Systems and 1 Million Improved Cook Stoves," presented at Ruposhi Bangla Hotel, Dhaka, 12 May 2013, http://www.pmo.gov.bd/index.php?option=com_content&task=view&id=1007&ltemid=353.

12 Practical Action, "Wind for Electricity Generation," Technical Brief (Bourton on Dunsmore, Rugby, Warwickshire, U.K.: undated), http://practicalaction.org/media/preview/10704.

13 J. Leary, A. While, and R. Howell, "Locally Manufactured Wind Power TechnologyforSustainable Rural Electrification," Energy Policy, vol.43 (2012).

14 Practical Action, "Micro-hydro Power," http://practicalaction.org/micro-hydro-power, viewed 18 February 2014.

15 B. P Koirala et al., Interconnected Mini-grids for Rural Energy Transition in Nepal (Lalitpur, Nepal: Alternate Energy Promotion Centre, 2013).

16 Sierra Club, "The Water Wheels of Time: Micro Hydro Power in the Western Ghats of India," Compass, 20 June 2011, http://sierraclub.typepad.com/compass/2011/06/the-water-wheels-of-time-micro-hydro-power-in-the-western-ghats-of-india.html.

17 Thailand Department of Alternative Energy Development and Efficiency, Thailand Energy Situation 2006 (Bangkok: 2007).

18 Sivan Kartha, Gerald Leach, and Sudhir Chella Rajan, Advancing Bioenergy for Sustainable Development: Guideline for Policymakers and Investors, Volumes I, II and ///(Washington, DC: World Bank Energy Sector Management Assistance Programme, April 2005), http://www.energycommunity.org/documents/SustainableBioenergyFinal.pdf.

19 Schnitzeretal., op. cit. note 7.

20 Ibid.

21 Debajit Palit, The Energy and Resources Institute (TERI), personal communication with REN21, December2013.

22 UN Development Programme, UNDP and Energy Access forthe Poor Energizing the Millennium Development Goals (New York: October 2010), www.undp.org/content/dam/aplaws/publication/en/publications/environment-energy/www-ee-library/climate-change/undp-and-energy-access-for-the-poor/2593. EnergyAccess_Booklet_Revision02.pdf.

23 World Bank, Scaling-Up Access to Clean Cooking Technologies and Fuels in Sub-Saharan Africa (Washington, DC: 2012), http://siteresources.worldbank.org/EXTAFRREGTOPENERGY/Resources/WorldBank_ACCES_AFREA_AFTEG_ESMAP_FINAL.pdf.

24 Franck Jesus, Global Environment Facility, personal communication with REN21, January 2014.

25 Global Alliance for Clean Cookstoves, "The Solutions: Cookstove Technology," http://www.cleancookstoves.org/our-work/the-solutions/cookstove-technology.html, viewed 21 January 2014; Arnaldo Carvalho, Inter-American Development Bank(IDB) Multilateral Investment Fund (MIF), personal communication with REN21, December 2013. Gasifier stoves are generally less efficient than forced air stoves.

26 IFC, op. cit. note 10.

27 Ibid.

28 Global Alliance for Clean Cookstoves, op. cit. note 25.

29 International Institute for Applied Systems Analysis (IIASA), "Chapter 19: Energy Access for Development," in Global Energy Assessment: Toward a Sustainable Future (Cambridge, U.K.and Laxenburg, Austria: Cambridge University Press and NASA, 2012), http://www.iiasa.ac.at/web/home/research/Flagship-Projects/Global-Energy-Assessment/GEA_Chapter19_energyaccess_hires.pdf.

30 Wim van Nes and Felix ter Heegde, SNV, "Building Viable Domestic Biogas Programmes: Success Factors in Sector Development," prepared forthe Asia Clean Energy Forum, Manila, 2-7 June 2008, http://www.thepowerofhow.org/uploads/wysiwyg/documents/other_resources/snv/Building_viable_domestic_biogas_programmes.pdf.

31 Frank Haugwitz, Asia Europe Clean Energy Advisory Co., persona communication with REN21, December2013.

32 Note that Indian figures are for fiscal years running April to March, with the 4.7 million mark likely estimated in March 2013, perlndian Ministry of Newand Renewable Energy, provided by Hari Natarajan, Deutsche Gesellschaftfur Internationale Zusammenarbeit- India, personal communication with REN21, December 2013. Construction was under the National Biogas and Manure Management Programme, and India had a total of 4.68 million plants as of October 2013, per SNV World, "Almost 42,000 small-scale biogas plants constructed in the first half of 2013," 5 December 2013, http://www.snvworld.org/en/sectors/renewable-energy/news/almost-42000-small-scale-biogas-plants-constructed-in-the-first-half.

33 Nepal installed an estimated 290,508 units under the National Biogas Programme, per Global Alliance for Clean Cookstoves, op. cit. note 25; Kenya installed an estimated 9,046 units under the Domestic Biogas Programme, perEnergyfor All, "Almost 34,000 small-scale biogas plants constructed underSNV supported programmes in Asia in the first half of 2013," 7 October 2013, http://www.energyforall.info/almost-34000-small-scale-biogas-plants-constructed-snv-supported-programmes-asia-first-half-2013/.

34 Solar Cookers International Network, "News and Recent Developments," http://solarcooking.wikia.com/wiki/Nepal, viewed 18 December 2013.

35 Bozhil Kondev, GIZ, personal communication with REN21, January 2014.

36 Global Alliance for Clean Cookstoves, op. cit. note 25.

37 P. Raman etal., "Evaluation of Domestic Cookstove Technologies Implemented Across the World to Identify Possible Optionsfor Clean and Efficient Cooking Solutions" (New Delhi: TERI, October 2013).