Tag Archives: photovoltaics

What Could The Energy Transition Be For Thermal Energy Services in the Global South – Part 3

Following our previous post on heating, this last post will investigate other energy service needs linked notably to farming activities.

Refrigeration/Drying

Refrigeration in developing countries in remote areas is rarely found except for specific needs like to keep vaccines for health centres. A number of possibilities exist to provide refrigeration with LPG, with passive solar, and again using ground-source heat pumps, but it seems solar PV is the most economical one. Various attempts have been made at renewable refrigeration over the past 30 years, predominantly focusing on solar collector designs, although photovoltaic vapour compression systems are the most commonly found for vaccine refrigeration. The high cost of these systems can often be justified by the importance of the application.

Larger refrigeration systems based on solar collection/kerosene/LPG power using different absorption refrigeration cycles (for example the Platen-Munters ammonia-water-hydrogen continuous diffusion absorption cycle) have been tested for ice-making in developing countries, but the lack of constant heat sources in renewably-powered systems has made reliability and efficiency a concern. Alternatives do exist to LPG-powered refrigeration in the form of solar refrigeration however, and with the current global lowering of photovoltaic and other solar components, the technology is becoming more cost-effective and viable to small entrepreneurs.

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Platen-Munters absorption refrigeration system and cycle. Image – centrogalileo.it

Drying is to be found in agriculture, but not at a small scale for individual households. Tray design solar dryers can be useful for small agricultural businesses to increase productivity, and are often easy to construct from locally-sourced materials. Updraft-style solar dryers are more complex from a design perspective, requiring specific attention to be paid to air flows and moisture extraction from the heating areas.

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Solar drying for chilli pepper crop in Peru, with locally-produced equipment. Image: Carlos Bertello, GIZ EnDev Peru.

Other Agricultural Uses

Milk pasteurisation is a critical issue for dairy farmers in the developing world. It has been estimated that over 50% of an average rural dairy farmer’s milk crop in Kenya will spoil before it has been sold, which has a severely detrimental effect on their livelihood and income generation. Modern pasteurisation equipment using steam boilers and batch-type pasteurisers can significantly increase output and income from a rural dairy farm in the developing world.

These steam boilers can be renewably powered, for example through biomass from animal/crop waste. Low-temperature (70-80°C) water can be substituted for steam in the pasteurisation process with only slight plant modifications, and this allows the potential for greater renewable energy use in the process, for example through flat-plate solar collector water heating, or cogeneration/recuperation from electricity generation or refrigeration equipment condensers. Whilst renewable pasteurisation technology has not been a focus of many organisations, the FAO have produced a report on the potential uses and processes for the technology, which is available here (http://www.fao.org/docrep/004/t0515e/T0515E03.htm).

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Potential for novel pasteurisation technologies in the developing world, to be powered by renewable electricity from solar or biomass digesters. Image: Openideo, Sarah Rizk, Stanford University.

In conclusion of this series of three posts, there exists vast potential over the wide range of available thermal energy services for the residential, industry and commercial sectors, notably in the Global South in general, and Sub-Saharan Africa specifically. The STEPs project will specifically be working most on the services that appear most viable in the Sub-Saharan African context: cooking/heating services for household needs, and low-temperature hot water production for households. The need for sustainable cooking and household thermal energy is a pressing one, and the STEPs project, through investigating a technology-neutral approach to thermal energy services and business, hopes to address this need.

– Xavier Lemaire & Daniel Kerr – UCL

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Energy for Development Case Study – Replication of Rural Decentralised Off-grid Electricity Generation through Technology and Business Innovation

Prof. AbuBakr Bahaj and Rucha Amin from Southampton University write on the University’s Energy for Development (E4D) project, providing renewable and reliable power to rural Kenyan communities.

Reliable and affordable sources of energy are fundamental not only for wellbeing, but also for economic growth and poverty reduction. Rural communities that do not have access to the national electricity network are also deprived of the associated benefits in health and quality of life provided by electrical services such as lighting and refrigeration. Fulfilling the energy needs of developing countries without compromising the environment is a challenge requiring imaginative policies and methods.

The approach adopted by E4D in Kitonyoni, Kenya focussed on a replicable, community based solar mini-grid electrification system aimed at invigorating village trading centres and promoting business innovation. The core of the project is based on a 13.5 kWp solar photovoltaic (PV) array with integrated rainwater harvesting system coupled to a mini-grid. The latter provides power to all trading centre buildings (shops, cafes, schools, health centres, churches etc.) and local businesses that in turn are able to provide charging facilities for electrical appliances, such as LED lanterns and mobile phones, to customers.

A major focus of this project has been to establish an economically sustainable system whereby the community contributes to the project and is responsible for the operation and maintenance of the plant. Income is generated for the cooperative which is also set up as an energy supply company (ESCO) through membership fees, local sales of electricity and share ownership. This income covers the running costs of the project, provides finances to the community as well as contributing to the recovery of the capital cost of the project.

Soton E4D ImageThe E4D project solar installation in Kitonyoni, Kenya. All images Sustainable Energy Research Group, University of Southampton

Since the installation in September 2012, there are clear indications that the trading centre in Kitonyoni is being transformed with land prices increasing, a number of new buildings constructed, new businesses opening and existing business owners reporting profit increases.  There has also been a marked improvement in healthcare provisions with a newly donated, fully electrified maternity clinic in operation. Furthermore, one replication project has already been carried out in Bambouti, Cameroon with a third installation in Oloika, Kenya planned for later this year.

For more information: http://www.energyfordevelopment.net/

– AbuBakr Bahaj and Rucha Amin, Southampton University

South Africa’s Renewable Energy Procurement Program

Robert Aitken from Restio Energy offers his thoughts on South Africa’s renewable energy procurement program to date.

South Africa has undertaken a very ambitious renewable energy programme which has the world watching with great interest. It has been said that the current programme to secure 3720MW of renewable energy is the largest in the world at this point in time. The approach used by the government is a competitive bid scheme (IPP Procurement Programme) where the private sector is invited to submit proposals against a stipulated amount of renewable energy required. Each of the identified renewable energy technologies has an associated tariff cap beneath which the bid must sit. The renewable energy technologies involved include; on-shore wind, solar PV, concentrated solar as well as a small amount of biomass, biogas and small-hydro.

It is an innovative and effective scheme which has thus far has been heavily over-subscribed in each of the three rounds assessed. It represents an important step for South Africa for a number of reasons;

  • This is the first large scale utility based renewable energy project in the country.
  • It will provide security of supply by diversifying the generational mix (previously predominantly coal) of electricity in the country
  • It has an increasingly demanding ‘local content’ or localisation component which is intended to stimulate the local renewable energy technology industry
  • It also has a strong community component aimed at ensuring local communities in and around these utilities benefit in a meaningful way.

It is these sorts of parallel requirements that will contribute towards the long-term operations and imbedding of renewable energy in the country. However, one of the service gaps this initiative will not address is access to electricity. The REIPPPP is a powerful grid security initiative which demonstrates the country’s willingness to engage with the private sector, promote renewables etc. Despite this 3.4 million households within the country remain without a grid connection and many households that are electrified cannot afford to use electricity particularly for thermal applications. While security of supply is crucial, the South African government needs to ensure a mixed approach (grid/off-grid, rural energy service delivery, small scale distributed initiatives, etc.) if access for all is to be achieved.

– Robert Aitken, Restio Energy