HOW TO BUILD A MICROGRID

While developed countries have enjoyed access to reliable electricity for nearly a century, energy access across the world remains one of the greatest challenges of our time. Globally, over 1 billion people still live without access to electricity today, putting them at a major developmental disadvantage. It has been shown that access to energy stimulates economic activity in a virtuous cycles: communities with power enable children to study during the night hours with electrical lights, community can charge cell phones to stimulate their business activities, and households can in many cases maintain appliances that raise their standard of living. Recently, the idea of a microgrid, a self-sufficient energy system that can operate independently from the larger grid has been receiving more and more attention due to its capability to address energy access challenges, especially in remote rural regions where grid development can be both economically and technically challenging. Microgrids have also gained popularity in developed nations, as they allow for greater independence from the larger electricity grid which can lead to more reliable energy infrastructure for the microgrid user.

Schematic Of A Microgrid with Utility Interconnection – Source: Microgrid Institute

These types of systems are sometimes also referred to as distributed generation systems, as some of them cannot operate as an “island” grid on their own. The scale of energy access challenges immense, extending from remote rural areas to the urban poor to name a few, and so are the complexities and intricacies of the various challenges. Microgrids provide an additional tool to help address the global energy access challenge and create more secure and sustainable energy infrastructures across the world. This tool, however, has to be completed with smart energy policies, as well as innovative business models and financing schemes to be utilized in an effective manner.

Even though a microgrid may take many shape and forms depending on its purpose and economic environment, the technical framework for many microgrid systems often remains fairly consistent. Generally speaking, four primary, five if it includes a utility connection, components are needed to build a functioning microgrid:

  • Power Source

The first component needed in any microgrid system is the power source. The energy source is often adjusted for the demands on the microgrid, such as the generating capacity desired, as well as other considerations. Solar power has been a increasingly popular energy source for remote microgrid providing energy access to rural areas in Africa. Recent price drops in photovoltaic solar power modules have been the economics of solar based microgrids more favorable, and the accessibility of solar energy in Africa further enhances the favorability of using solar power.

Solar Modules For A 700 W Microgrid in Kokota, Tanzania – Source: Permaculture Research Institute

Some of the primary challenges for solar based remote microgrid are maintenance of the modules, whose performances can decrease significantly when exposed to high moisture levels, as well as the storage requirement that the intermittent source imposes. This is particularly important in economic considerations, as storage systems generally make up the bulk of microgrid costs and more solar capacity requires larger storage capacities. Further power sources that have provided energy areas in remote rural areas include small hydropower stations, as well as wind power. In developed countries many microgrids operate with natural gas as a power source.

  • Power Management System

The power management system handles the transfer of electrical power from the power source to the electricity consuming devices. These type of electric load management usually requires converting the electricity generated from the power source with an inverter that transforms the electricity to the form required for most appliances, such as cell phone or cooking equipment, and interfacing with the storage components of the microgrid to balance the supply and demand loads of the microgrid. Modern microgrid systems often integrate software and control systems, such as smart meters, that can manage the grid operation in an efficient and reliable manner.

  • Energy Storage System

Storage systems are essential to any microgrid because they allow the microgrid to balance the electrical and thereby make the electricity accessible when it is required by the user. A review of common energy storage technologies for various capacities can be found here. In the case of remote microgrids, batteries are the most common storage technology often because the storage capacity required fort he microgrid does not justify the higher cost of other storage technologies. Large-scale storage technologies, such hydro based storage or thermal storage, have high initial costs that make their implementation in remote microgrids challenging.

Power Management and Energy Storage System For A Microgrid – Source:Aquion Energy

  • Electricity Consuming Devices

The last component of the microgrid are the electricity consuming devices whose energy is supplied from the overall microgrid system. It is important to consider these devices because they will dictate the electrical loads placed on the microgrid, which in turn will affect the power generating capacity required from the power source and the storage requirements. Charging a cell phone, for example, generally places a small capacity requirement on the overall system whereas connecting a refrigerator to a solar-based microgrid can create difficulties managing electric loads due to the significant constant power demands of the appliance.

  • Utility Connection

Many microgrids in developed countries, such as the schematic shown earlier, also have an integrated connection to the larger utility. This connection enables the mirogrid to exchange power with the larger utility network. This type of microgrids with utility connections are common for university or corporate campuses and hospitals.

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ENERGY ACCESS ACROSS THE WORLD

In North America and Europe energy access is not a severe issue with all developed countries having 100% electrification rates across the board. In the developing world, however, access to energy remains a major obstacle for common people. Electrification has been largely resolved in urban areas, with the majority of urban areas across the world having electrification rates over 90%. Energy access in rural areas, however, remain a major issue as can be seen from the map below:

The map above shows clear disparities in rural energy access between the developed world and the developing world. The good news is that most of the world has been able to connect its population to a reliable energy infrastructure; the bad news is that in nearly all of rural Africa, as well as some rural areas South East Asia and Latin America, still lack basic energy infrastructure. The situation is particularly disheartening in Africa where the majority of the rural population outside of North Africa still lacks a reliable grid for their energy needs. This clearly demonstrates the need for innovative energy access technologies to bridge the gap in the economic disadvantages resulting from lack of energy access. Some of the major economic disadvantages that can result from inadequate energy access include limited access to crucial technologies, such as reading lights, cell phones for business purposes and cooking tools that do not rely on biomass. Furthermore, lack of energy access can be related to a lower quality of life due to lack of refrigeration and substantially less developed health infrastructure.

While the energy access situation for rural Africa depicted in the map above may be disheartening, it also presents an enormous opportunity to deploy innovative energy systems on the continent. Since grid expansion in rural Africa can be prohibitively expensive, $20,000 per kilometer in Mali for example, many of these new energy schemes have relied on off-grid distributive energy generation that have often been based on renewable energy sources. This has created an immense opportunity for rural Africa to leap off grid with a variety of technological and business innovations as described in this previous BERC article.

The energy access crises and opportunities presented in South-East Asia have caught the attention of UC Berkeley students that founded the cross-disciplinary BERC community of CAL-RAE lead by UC Berkeley student Jalel Sager and UC Berkeley alumnus Austin Cappon. CAL-RAE is a BERC community that brings together UC Berkeley students from different disciplines to put distributed renewable energy systems on the ground in South-East Asian countries, such as Vietnam. CAL-RAE recognizes the importance of interdisciplinary collaboration given that setting up an off-grid energy system requires engineering, financing, and business logistics efforts to name a few.

Another BERC community focusing on rural energy access issues is the Berkeley Rural Energy Group (BREG), which is comprised of NGOs, technology firms, Berkeley students, and Berkeley faculty from diverse fields of study. Their focus is to build a Bay Area community of passionate experts on energy access and rural energy development, and to provide expertise to outside parties interested in bringing access to developing countries.

This article is part of a new BERC series highlighting the issue of energy access. Be on the lookout for more posts on this topic in the coming weeks

Africa’s new breed of solar energy entrepreneurs

By Tom Jackson
Capetown
Let there be light: A new breed of entrepreneur is bringing solar power to millions of Africans who don’t have access to mains electricity.

African economies may be booming, but continued growth and quality of life are being jeopardised by lack of power.

The International Energy Agency (IEA) estimates 585 million people in sub-Saharan Africa lack access to electricity, with the electrification rate as low as 14.2% in rural areas.

The problem is most acute in East Africa, where only 23% of Kenyans; 10.8% of Rwandans; and 14.8% of Tanzanians have access to an electricity supply, according to the World Bank.

In spite of efforts to get people onto the grid, population growth has meant these figures stay fairly steady, with the majority of people still using costly and unhealthy forms of energy for cooking and lighting.

A number of companies and organisations on the continent have identified solar power as the solution.

And a new breed of “solar-preneurs” is emerging, increasing access to power and generating revenues at the same time.

Solar arrayThis solar array is in Morocco, but harnessing solar power doesn’t have to be done at this scale
Solar-powered street light in MaliSmall, portable units like this solar-powered street light in Mali can make major changes to a community

Modular living

“Solar is a valuable source of distributed energy,” says Sachi DeCou, co-founder of Juabar, a company operating a network of solar charging kiosks in Tanzania.

“In many places in sub-Saharan Africa, populations are quite dispersed. Solar is modular so it can be sized to fit the needs of anywhere, from a light to a business, household to an entire village.”

In agreement is Jesse Moore, managing director at M-Kopa Solar, which provides “pay-as-you-go” renewable energy for off-grid households in Kenya, Uganda and Tanzania.

Off-grid households in East Africa, which also are largely low-income households, spend about $0.50-$0.60 (33p-40p) per day on kerosene lighting and basic charging costs, he says.

M-Kopa Solar customerM-Kopa Solar provides pay-as-you-go energy to people off the grid paid for by mobile money transfer
M-Kopa Solar kitThe kit comes with several lights, a torch, a solar radio, a USB phone charging port and a solar panel

“With more than 20 million homes off the grid, this means over $3bn (£2bn) is spent each year on these inefficient and unsafe energy substitutes.”

Given the inefficiencies and high costs associated with alternative power sources, solar has proven hugely popular in places where it has been available.

M-Kopa Solar provides power to more than 140,000 households in East Africa for $0.45 per day, and is adding over 4,000 homes each week. And with this increased uptake comes economic opportunities for the companies that provide it.

M-Kopa Solar’s revenues are nearing $20m per year, and the company is starting to licence its technology in other markets, such as Ghana.

“M-Kopa is demonstrating that off-grid energy will be as revolutionary to Africa in the coming decades as mobile telecommunications have been in recent years. Solar is a massive opportunity for entrepreneurs and investors alike,” Mr Moore says.

Build a business

Other business models are seeking to allow ordinary African individuals to start their own solar businesses.

Ms DeCou’s Juabar, for example, builds and operates a network of solar charging kiosks in Tanzania which it leases to entrepreneurs, who then offer electricity services to their communities.

Juabar’s entrepreneurs are currently earning profits of between $75 and $150 per month, with the company currently leasing out 30 kiosks to Tanzanians and looking to raise $15,000 through crowdfunding in order to increase that number to 50.

“There has been a lot of development in the pay-as-you-go solar space over the past few years, facilitating access by reducing the upfront costs of purchasing a solar system,” Ms DeCou says.

New solar kiosk entrepreneurs being trained by JuabarNew solar kiosk entrepreneurs being trained by Juabar

“As we continue to make solar technology more widely available and affordable, one of the most exciting areas of opportunity becomes what you can do with this solar electricity.

“Solar is a source of reliable, accessible electricity. Once you can develop that access you have the opportunity to develop new ways to use that electricity to meet community needs. That is what I get most excited about.”

Henri Nyakarundi is employing a similar model in Rwanda. His company has developed a mobile solar charging kiosk.

The kiosks are operated under a franchise model, offering Rwandans the chance to run income-generating businesses by providing services such as charging of electronics and sales of electronic vouchers.

Wi-fi hotspots will be available from the kiosks soon – there are already 24 up and running with another 100 due this year.

Mr Nyakarundi says he plans to offer a single distribution channel for different products, services and content, while providing opportunities for entrepreneurship through a low-cost franchise model.

He believes the opportunities to create solar businesses in Africa are “huge”, but as yet, they only exist at the micro level. The next step, he believes, is to move to the macro level – producing power for the grid through solar.

“However macro level requires large investment, and unfortunately local banks are still not willing to finance such projects unless you are a big company,” Mr Nyakarundi says.

One of Henry Nyakarundi's solar powered phone charging stations in RwandaOne of Henry Nyakarundi’s solar-powered phone charging stations in Rwanda
Phones being charged at a mobile solar powered charging stationPhones being charged at a mobile solar powered charging station

Ms DeCou and Mr Moore cite different issues, with the Juabar co-founder saying there was a lack of adequate data on population density in the areas where the company works.

“We do our own research to determine ideal places for expansion, as there is limited access to reliable maps of population distribution,” she says.

Mr Moore says the main obstacle to the growth of solar in Africa is the unaffordability of purchasing solar power “up front” for consumers, though he believes M-Kopa Solar has been so successful to date because it addresses the affordability barrier head on.

Governments see the light

As the likes of Ms DeCou, Mr Moore and Mr Nyakarundi look to boost access to solar and the entrepreneurial opportunities associated with it, assistance has been on hand from east African governments.

Ms DeCou commends the Tanzanian government for not charging Value Added Tax (VAT) on solar products, which she says is a great support to the industry and helps to increase access.

“Beyond that, there are specific government programmes to help facilitate rural energy access,” she adds.

“East African countries offer VAT exemption on all solar products, which is a big saving for a small company like ours,” Mr Nyakarundi says.

“It will be great to see an east African R&D [research and development] fund for local entrepreneurs that wants to develop new innovative technology to solve our local challenges, so we can stop just importing foreign technology – which most of the time is not designed for the African market – and create a new industry that can level the playing field between Africa and the rest of the world.”

AFRICA LEAPING OFF-GRID

Cross-posted from the Stanford Energy Journal.

Sub-Saharan Africa is one of the least developed areas in the world. According to the World Bank, of the approximately 940 million people living in the region, roughly 600 million lack access to electricity. Moreover, the number of people in Sub-Saharan Africa without electricity has actually been increasingas the population growth has outpaced the rate of electrification. Lack of access to electricity greatly limits the development prospects of these, largely rural, Africans, as they are greatly limited in their performance of basic tasks, such as reading at night. Furthermore, communication with the outside world is heavily restrained, as there is limited access to telecommunications and the Internet. To meet their basic energy needs, many Africans then resort to primitive sources of energy, such as kerosene lamps or burning of biomass, that are both expensive and environmentally damaging. Even those primitive energy sources can be hard to come by, with some rural women in Tanzania walking 5-10 km a day to obtain 30 kg of firewood. The consequences of this underdeveloped energy infrastructure therefore include not only a loss of developmental opportunity, but also a higher cost for basic needs.

Grid expansion in rural Africa, where the population density is only five people per square kilometer, has been occurring very slowly. To make matters worse, in addition to poor reliability and connectivity, grid electricity is often too expensive for Africans to afford. In sparsely populated countries, such as Mali, grid expansion can cost up $19,000 USD per kilometer, which is too expensive for African consumers to afford and African governments to subsidize. Azuri Technologies, a UK based company providing cell phone charging solutions in rural Africa, estimates that a single cell phone charge in Africa, which costs about 20 cents, is about 100 times more expensive than in developed countries. This dire situation of poor electricity infrastructure, however, may have a silver lining, as it has opened the door for new off-grid energy innovations to potentially circumvent current energy technologies in developing countries.

Similar to how cell phones leapfrogged the development of a telecommunications grid in Africa, the lack of energy infrastructure in Sub-Saharan Africa has enabled the development of a new energy landscape that is entirely based on off-grid renewable energy technologies. Many of the most successful such systems have been solar modules that store energy in a small battery.  Solar energy is particularly favorable for rural Africa given that the continent has one of the highest solar irradiances in the worlds. Many African countries receive 325 days of bright sunlight per year, which gives a steady supply for solar powered systems. Furthermore, unlike diesel and kerosene that require repeated supplying of fuel, solar modules only have to be transported to their place of use once. The main obstacle for solar power is the high initial cost of the systems. These high initial costs of renewable energy sources coupled with the low incomes of people in Sub-Saharan Africa has led companies to explore novel financing schemes. UK based Azuri Technologies, BBOXX, and San Francisco based Fenix International are examples of companies that have been able to change the business model of renewable energy to a “pay-as-you-go” system resembling the pricing scheme of traditional grid. This model is structured in a way that allows the user to pay for the system over a longer period of time, such as 18 months, thereby decreasing the initial investment required to obtain such a system.

The introduction of these small energy modules has not only enabled many Africans to meet their basic energy needs using solar power, but it has created numerous opportunities for entrepreneurs as well. Enterprising individuals who have used their solar modules to power cell phone charging businesses are a great example of how these systems can spur economic development. Moreover, given the importance of wireless communication to the vitality of rural Africa, the increased availability of charging for cell phones then catalyzes further business development across many previously unconnected areas.

http://commons.wikimedia.org/wiki/File:Charging_mobile_phones_and_light_bulbs_is_a_business_inside_UN_House,_Juba_(12317290513).jpg

Charging a cell phone in Africa could be 100x more expensive than in developed countries.
(Image: Oxfam East Africa, Wikimedia Commons)

Even though solar power is the most promising renewable energy technology for Africa, there are various other promising sources available for renewable energy development. There are massive potential sources available for hydropower in the Ethiopia and the Democratic Republic of the Congo. Furthermore, most of West Africa has abundant sources for wind power. There are even significant geothermal power sources in many East African countries. Yet, many of the above renewable energy technologies, especially hydropower and geothermal power, require grid infrastructure to function properly. The high cost of grid expansion, and the substantial investments required in building these types of power plants, makes it very unlikely that these types of renewable energies will be integrated without outside financial support.

Wind power could be an alternative to solar powered distributed generation, but wind turbines are more difficult to build in remote areas, and require higher maintenance efforts during their use. This is different from solar systems, which are already being sold in plug-and-play systems that are easy to use. One significant disadvantage of wind and solar are their irregular energy generation patterns that can make it difficult to operate larger devices, such as fridges or small machinery. Energy storage technologies, such as batteries, are often used to address this problem for wind and solar, but storage then adds further cost and complexities to the systems. This can cause significant maintenance problems in larger off-grid systems that cannot fit into small ready-to-use modules given that technical support will be difficult to obtain in these very remote areas. Given that problem, another promising off-grid alternative is micro-scale hydropower. Even though the initial micro-hydro system may be more difficult to install, after the system has been built, a micro-hydro can provide a steady supply of energy to a remote community. The steady, reliable supply of energy constitutes a significant advantage over solar and wind power as it provides a base load of energy. Since many communities are located near some type of water, micro-hydro could fill a different type of energy than the already successful solar modules.

This exciting development of off-grid renewable energy technologies in rural Africa is not only catalyzing economic development for disadvantaged populations, but it may also foreshadow how the energy system of the future will look. Constructing an electricity grid is an expensive and complex operation that requires the cooperation of many different entities, while small off-grid energy systems have proven to be easy to use and deploy. As these systems continue to develop they will be able to meet increasingly greater energy needs, such as enabling the use of refrigerators, and spur increasingly complex types of economic development. Developed countries are also discussing decentralization of the electricity grid as renewable energy sources combined with energy storage systems begin to make distributed generation a feasible option. Africa’s leapfrogging of the traditional energy infrastructure may just provide the insights we need to redesign the current grid into a decentralized, renewable energy based energy system.