Homes and other buildings have a direct impact on the environment due to the construction process utilized to build them, the materials used, and the design features. Traditional homes have typically had a negative impact on the environment, contributing greenhouse gases into the air with heating, cooling, and other types of energy usage. Sustainable building is gaining traction as more people seek to reduce the negative impact of their homes on the environment. Earthships are one sustainable home option, created by architect Michael Reynolds. These structures are designed for independent operation off of the grid, minimizing their negative impact on the environment. Some municipalities are developing special sustainable communities with Earthship homes for sale.
History of Earthships
Earthships have been evolving for more than 40 years with home designs that can exist in harmony with the environment. Reynolds receives credit as the mastermind behind the concept of Earthships. Reynolds’s vision has involved redefining architecture to build homes that need no energy or very little energy, both during the construction process and after. The name “Earthship” was created for these homes because they are self-sustaining structures. This means that they use renewable sources of energy such as the sun, wind, and water to power the home.
Construction and Design
Earthships contain both recycled and natural materials, earning them the label of “carbon-zero” homes. Contractors scour landfills to find suitable building materials for constructing Earthships. Materials such as discarded tires, aluminum cans, and glass and plastic beverage bottles have been collected for use in building Earthships. Mixing old tires with compacted soil creates an exceptionally strong material suitable for outer walls and load-bearing interior walls. Aluminum cans may be the main material used to construct other interior walls. These homes even utilize discarded panels from appliances such as washing machines and refrigerators in their construction. In addition, Earthships are built to coexist with and integrate into their surrounding natural environment. These homes have a soil thermal wrap around them, which helps regulate the interior temperature of the homes. Earthships often have at least two sides that are built into the earth. The roof design of Earthships enables harvesting of rainwater to divert into the home. After filtering the rainwater, homeowners can use it for laundry or cleaning.
Generation and Use of Power and Water
Earthships are independent structures, producing the power needed for their heating, cooling, water generation, water heating, sewage, lighting, and general electricity. With the installation of special organizing modules that collect energy from the sun and wind, Earthships save this energy for use in the home. Special batteries will hold the energy until the home needs it for heating or cooling, for example. The batteries will also use the energy for other processes in the home, such as operating a washing machine, kitchen appliances, and electrical devices. After collection of rainwater in cisterns, a special water organizing module filters and pumps the water into a pressurized tank for use in the home.
Examples of Earthships
A number of different Earthship designs are in active use around the world. As research and technology continues to expand, Earthships evolve with new designs and features. Some people opt for a custom Earthship with features that are built to exact specifications. This type of Earthship is the most expensive type of home. Other models are more economical because they have standardized features. Earthships can be designed and built for virtually any geographical location, including tropical parts of the world.
How to Acquire an Earthship
Acquiring an Earthship involves learning about this type of home and then planning the location of it. Choosing the location of the Earthship is an important part of the planning process, due in part to the permit process that is typically involved. It’s possible to build an Earthship in any climate, so geographic location need not be limited based on this factor. But some locations may be less expensive for building due to varying prices in sustainable building materials. Anyone wishing to build an Earthship should research possible locations, including the terrain and geographical features, as well as permits required.
KAMPALA, UGANDA – African governments wishing to attract private sector money to pay for new badly needed power projects are expected to send representatives for the Africa Energy Forum scheduled for London on June 22nd.
“Being in London, the world’s finance capital, will enable Africa’s growing number of power developers to showcase their businesses to decision makers of the world’s most prolific investment organisations from around the globe,” Shiddika Mohamed, the Group Director of EnergyNet Limited and main organisers of the talks said last week.
The Africa Energy Forum which is the annual global investment meeting for Africa’s power, energy, infrastructure and industrial sectors.
The event is expected to bring together 1,000 investors, 500 public sector stakeholders, 300 technology providers, 270 developers and representatives from 70 countries.
According to a company statement, “The decision to move the forum to the UK this year, was taken to capitalise on the investment potential of the UK and promote the strong trade relationship between the UK and Africa’.
The last three forums were held in Dubai in 2015, Istanbul (2014) and Barcelona (2013).
The African Development Bank (AfBD) says the entire installed generation capacity of Africa’s 48 sub-Saharan countries is just 68 gigawatts, no more than Spain’s.
As much as one-quarter of that capacity is unavailable because of aging plants and poor maintenance.
More than 645 million people in sub-Saharan Africa — roughly 70% of the region’s population — do not have access to electricity. If current trends continue, fewer than 40% of African countries will reach universal access to electricity by 2050.
This lack of adequate power supplies continues to be a major deterent for investment. Per capita consumption of electricity in Sub-Saharan Africa (excluding South Africa) averages only 124 kilowatt-hours a year and is falling. The rate of consumption is barely one percent of that in high-income countries. If entirely allocated to household lighting, it would hardly be enough to power one light bulb per person for six hours a day.
This year sees the Forum hosted in London for the first time – at the new London Intercontinental O2 overlooking the skyscrapers of the Canary Wharf and the famous River Thames.
New for this year will be the Growing Economies Energy Forum (GEEF), running alongside the Africa Energy Forum. GEEF will host a day of open discussions between the governments and private sector from new energy markets such as Iran, Pakistan, Myanmar and Peru, as these growing economies open up for international investment following political and economic developments.
EnergyNet will also host a typically English opening night pub quiz party on the evening of 21st June featuring some legendary British culture and food, allowing participants to network in a fun, laid back environment before the formal opening on the 22nd.
Speaking in Washington last month, Power Africa coordinator Andrew Herscowitz (a United States government initiative) said: “There is absolutely no reason the entire continent can’t be lit up because there is the money, the technology and the desire to make it happen. People have to be more forward thinking, forward leaning and have competition to bring costs down.’
Australia-based Austin Maynard Architects have recently completed a luxury home in Melbourne called That House. It’s ultra modern and very sustainable, with a footprint of about half that of the surrounding houses. The home is also powered by solar energy, and features a rainwater collection system.
That House is a unique two-story home, which is made from rectangular volumes stacked on top of each other. Together they yield an interior floorspace of 2,744 sq ft (255 sq m). The main living area of the home is located on ground floor, which features two lounges, a kitchen, a dining room, a study, and a bathroom. On the first floor there are three bedrooms, a bathroom and a toilet.
A narrow hallway separates the two areas on the ground level, which is an interesting design choice, given that the hallway is an indoor/outdoor kind and leads to the back yard on one end. The rectangular volumes that make up the home are reminiscent of shipping containers, though they are larger and feature glazing on the shorter sides, which lets in a lot of natural light. Since the layout of the ground floor is very open, the designers included hinged walls at strategic places, which can be used to gain some privacy. Since the home features ample glazing, the designers also installed shading, which pulls up, giving the occupants privacy with the option of still retaining the view of the sky.
The glazing was installed with passive solar gain in mind, and to this end there are no windows on the western façade, and very few on the eastern elevations. Rainwater is collected in a large tank buried in the garden, and this water is used for irrigation as well as flushing. The home was also very well insulated, and the PV panel array takes care of most of the household’s power needs.
Construction work has begun on Europe’s largest floating solar farm at the Queen Elizabeth II reservoir near London as part of Thames Water’s plans to source a third of its energy from renewable sources by 2020.
More than 23,000 panels will be floated on the reservoir, providing enough electricity each year to power the equivalent of around 1,800 homes. Due for completion at the end of March, the finished array will cover around a 10th of the reservoir’s surface – the same area as eight Wembley-sized football pitches.
The renewable electricity produced by the 6.3MW array will power a nearby water treatment centre, Thames Water said.
“Becoming a more sustainable business is integral to our long term strategy and this innovative new project brings us one step closer to achieving our goal – this is the right thing for our customers, the right thing for our stakeholders and most importantly the right thing for the environment,” energy manager Angus Berry said in a statement.
Solar energy company Lightsource is managing the installation, which will require more than 61,000 floats and 177 anchors to keep the array above water.
Lightsource chief executive Nick Boyle said that as more industries look to decarbonise, the solar industry will need to develop new skills to ensure projects deliver maximum efficiency.
“There is a great need from energy intensive industries to reduce their carbon footprint, as well as the amount they are spending on electricity and solar can be the perfect solution,” he said in a statement. “We’re therefore constantly evolving new skill sets to ensure that all of our projects deliver maximum energy generation over the lifetime of the installation.”
Floating solar farms are considered an efficient way to maximise renewable energy generation in areas where land is scarce, by using the normally redundant surface area on reservoirs and lakes.
The largest floating solar array is currently under construction on a reservoir in Japan. Once completed, it will provide enough clean electricity to power nearly 5,000 households.
Advocates of the approach argue it can also reduce evaporation from reservoirs, while the cooling effect of the water is said to help improve output from solar PV cells.
Production of electricity from waste has the potential of providing up to 83.8 TeraWatt hours (TWh), which is about 20% of the electricity needed in Africa by 2025. This is according to a study co-authored by the European Commission Joint Research Centre (JRC). However, this requires stringent waste management policies to be put in place, and today Africa lacks the adequate infrastructure needed to install these environmentally friendly methods.
Like some other parts of the world, most of the waste in Africa is burned without tapping the potential of gases (which usually end in pollution) or dumped in landfills without protecting groundwater. Many of the developed countries that have a high percentage of waste to energy recovery, have strict emissions laws that regulate waste handling.
Waste in Africa, according to JRC, can be used to produce energy in two ways. The first is using Waste-to-energy (WTE) incineration plants where the trash is burnt to produce steam that turns turbines. The report notes that these are few in this part of the world because of the high initial costs of establishment. Strict measures are needed to ensure the plants do not pollute the environment via toxic by-products.
Although most of Africa buries or dumps waste that when decomposing releases methane and carbon dioxide gases naturally. These gases can be captured for heat or burnt in gas turbines, internal combustion engines, and steam boilers to produce electricity. This is the second method.
Waste energy recovery could act as one stone killing two birds because it provides power, and at the same time helps deal with the increasing waste problem in Africa. The continent is expecting incredible growth in population and urbanization, which is to be accompanied with production of more waste. The reports points out that energy recovery from waste could help alleviate energy poverty in countries such as Central African Republic, Burundi, Guinea-Bissau, Mali, Sierra Leone, Rwandaand Somalia, which have poor access to electricity and low electricity consumption per capita.
The potential could be much higher since the 20% figure is based on urban waste calculations alone according to the report. Most of waste around the world is concentrated around urban centers.
A few projects already underway
Just recently, Cleanleap wrote about Africa’s first and largest Anaerobic Digester (AD) which will generate 2.4 MW of installed power that will be channeled to Kenya’s national electricity grid. It first converts biomass waste (organic waste being sourced from nearby farms) to biogas and then the biogas is burned to produce electricity and heat. In addition to using 50,000 tones of organic crop waste each year, it will produce 35,000 tones of nitrogen-rich matter as a by-product natural fertilizer. The first phase of the project is now complete.
My colleague also recently wrote about an Ethiopia’s 50-year-old towering mountain of waste Koshe being converted into power. Koshe Waste-to-Energy facility will generate 50 megawatts of clean energy by burning 350,000 tones of waste annually. It will help deal with the waste menace. Construction of the factory started last year and was to complete in 18 months.
The Bill and Melinda Gates Foundation are also partnering to see the first Omni Processor factory pilot project thatconverts sewage into drinking water and power. The first factory will be based in Senegal and, although it is fronted as a project to mainly reinvent the toilet, it will produce 150W of power and the success of the pilot project would prove that the solution can be duplicated all over developing countries. It involves boiling of sludge to high temperatures to produce steam, which is then used to run steam engines. Construction of the factory begun last year.
These are just but a few of the thousands, but yet insufficient, projects being pursued to produce power from waste.
The issue of power shortages cannot be re-emphasized and introduction of off-grid solutions is seen as helpful towards increasing power access. In short, in addition to bringing a revolution to how we generate power so much needed in Africa, waste-to-energy projects will also help deal with sanitation problem in developing countries, one of the largest problems facing many of these nations and which is still responsible for many health problems.
Africa needs a new deal on energy, and now it has one. US President Roosevelt’s post-Depression New Deal of the 1930s focused on ‘Relief, Recovery and Reform’. For Africa’s New Deal on Energy, in the spotlight at the World Economic Forum in Davos this week, the focus is on Power, Potential and Partnership.
‘Power’ – because the New Deal aims to light up and power Africa by 2025. Energy is the lifeblood of any society. It is the passport to economic transformation, and it is one of the foundations for any society in the provision of education and health. And yet as we begin 2016 over 645 million Africans – some two-thirds of the people on the continent – have no access to energy.
Africans are tired of being in the dark: children suffer, because 90% of the continent’s primary schools have no electricity. Women suffer: 600,000 people, largely women, die each year from cooking with unclean energy like wood or baked earth. Hospitals and their patients suffer when equipment simply doesn’t work. Small and even large businesses suffer – Africa loses an estimated 4% of its annual GDP for the lack of energy. The unavailability of energy in Africa is unacceptable, and so is its cost. A woman living in a village in northern Nigeria spends around 60 to 80 times per unit more for her energy than a resident of New York City or London.
‘Potential’ – because Africa is aching to release its full economic potential, and to turn strong but uneven economic growth into deep-rooted and universally shared economic transformation. Energy is the secret to that. With a strong and secure energy supply we can unleash the skills of a young and dynamic population. We can continue the process of turning agriculture into agro-industry, and partial diversification into full-scale industrialisation. The raw materials that will provide our energy await us – unused or as yet untapped. As well as 300 gigawatts of coal potential and 400 gigawatts of gas, the continent is waiting to get its hands on 10 terawatts of solar energy potential, 350 gigawatts of hydroelectric, 110 gigawatts of wind, and a further 15 gigawatts of geothermal.
‘Partnership’ – because no country, no organization, no initiative can do it alone. The Africa Progress Panel has already done the research to show that Africa can power itself – if it and others work together. There are already key players in the field, like the Africa Renewable Energy Initiative supported by the G7, the UN’s Sustainable Energy for All Initiative, and the US Power Africa Program. The private sector is a source of leadership as well as funding, for instance through the Africa Energy Leaders Group. The task is to point them all in the same direction. So the New Deal is an African-led initiative to mobilize political will and financial support to solve Africa’s energy challenges.
What will it do?
It has four – huge – targets. To increase on-grid generation by adding 160 GW of new capacity by 2025, nearly doubling what we have today. To increase on-grid transmission and grid connections that will create 130 million new connections by 2025, 160 per cent more than today. To increase off-grid generation to add 75 million connections by 2025, nearly 20 times what we have today. To increase access to clean cooking energy for around 130 million households.
First and foremost, it will raise money, from Africa and beyond, and from the public and the private sectors. We need a total of $60-90 billion a year, compared with the $22 billion invested in the sector in 2014. This money will come from a variety of sources. First, we will work with other multi-lateral and bilateral financial institutions to see if we can get investment into the power sector to triple on an annual basis. Second, governments themselves need to play a role. If Africa were to increase its annual spending on energy from 0.4% of GDP to 3.4%, this would solve the problem completely. This could also be done by putting an end to subsidies for products such as kerosene and diesel. Finally, the private sector is very willing to play a significant role. This will require changes in regulation to make the sector more attractive for private capital, but we have seen many examples of significant capital flow where regulations are appropriately structured.
The New Deal is also practical: it will set up the right energy policy environment: laws, regulation, governance; it will build the capacity of national energy utility companies; it will dramatically increase the number of bankable energy projects and the funding pool to deliver them; it will roll out waves of country-wide energy ‘turnarounds’. It will be energy resource neutral, using renewables and non-renewables alike, and technology neutral.
The African Development Bank will manage the New Deal, as well as investing US $12 billion in energy funding over the next five years, attracting up to four times as much from other financiers in the process.
‘I pledge you, I pledge myself to a New Deal for the American people’, said FDR in July 1932. The pledges – financial and political – are being made again on a different continent, over 80 years later. Meeting Africa’s energy challenge is both a moral and an economic imperative. ‘A flick of a switch’ can’t be delivered in an instant, but a flick of a switch is what it will take.
The National Energy Regulator of South Africa (Nersa) will start its public hearings on Monday as part of Eskom’s application to recover an additional R22.8bn through an electricity tariff increase.
The Nersa public hearings will start in Cape Town and end in Midrand on 5 February.
Nersa approves electricity tariff increases for Eskom based on a number of assumptions on factors such as electricity demand and cost of primary energy. Depending on how those assumptions pan out, Eskom is either owed money or owes the public.
The methodology used to determine Eskom’s tariffs allows the utility, after the financial year-end, to submit its so-called Regulatory Clearing Account (RCA) application based on the financial statements. This is meant to reconcile the assumptions and projections used to determine the tariffs and the actual revenue costs incurred.
Eskom submitted an application for the 2013/14 financial year in November. An approval of the application could result in future tariff hikes. Eskom last week said an approval of the application would improve its ability to meet financial commitments and enhance its balance sheet.
In its application to Nersa, Eskom wants to recoup, among others, R11.7bn for a shortfall in revenue, R8bn in costs associated with the utility’s peaking open cycle gas turbine (OCGT) plants and R2.4bn for primary energy costs.
Eskom said the shortfall in revenue was primarily due to lower than anticipated electricity demand. The power utility said it had not included any revenue lost because of load shedding in 2013/14.
“Investors are seeking certainty and stability from the regulatory process,” Eskom said in a statement on Sunday. “Eskom has recently been downgraded by rating agencies and they note inadequate tariff increases as part of the reason for the downgrade.
“A favourable RCA process will improve investor confidence, which impacts our credit rating and funding security,” it said. “Funding security ensures that the build programme remains on course for completion.
“Sufficient revenue allows Eskom to continue with the generation performance improvement programme to the benefit of all customers. A financially sustainable Eskom will support our country’s broader economic objectives.
“Eskom’s 2013/14 RCA submission of R22.8bn is driven substantially by revenue under recoveries, higher expenditure on coal burn, independent power producers, open cycle gas turbines and other primary energy costs.”
EE publishers MD Chris Yelland, who was vocal at the previous public hearings in 2015, said this new application was problematic in the current economic situation.
Writing before the crisis stemming from former finance minister Nhlanhla Nene’s removal from Treasury, Yelland said: “Claw-backs via the tariffs will add significantly to the electricity price trajectory, over and above the 8% per annum granted by Nersa over the five-year MYPD3 period.
“A compounding problem arises from the elasticity of electricity demand in the face of steeply rising electricity prices significantly above the inflation rate, which further reduces electricity sales volumes and increases claw-back claims, in a vicious circle.
“With constrained supply and declining sales volumes, rising electricity prices reaching the limits of affordability, and the tipping point to grid defection in sight, Eskom’s future ability to finance its own generation, transmission and distribution activities comes into question.”
Solar energy received a boost on Monday, when Energy Minister Tina Joemat-Pettersson announced a new power procurement project in the Northern Cape to deliver 1 500 MW of solar energy.
The additional procurement was a Department of Energy legacy project to mark the SA International Renewable Energy Conference taking place in Cape Town this week.
“It is a ministerial legacy project to ensure we remember this conference,” the minister told media after her opening address on Monday.
The announcement is the first step in a process that will seek bids from independent power producers (IPPs) and will likely only feed into the grid between 2019 and 2020.
Renewable energy is gaining steam both in South Africa and globally and SA’s IPP programme has been heralded as a success story.
With a target of 5 000 MW of solar energy and 5 000 MW of wind energy by 2030 in place, the IPP office has successfully attracted much-needed investment in the renewable energy sector.
In April, the minister approved 13 new renewable IPP bids, which means there will now be 79 IPP projects with 5 243 MW being added to a national grid desperately in need of power.
“To date, more than 6 000 MWh of electricity had been procured from 37 renewable-energy IPPs,” said Joemat-Pettersson.
“To date, renewable energy projects in South Africa have resulted in 20 000 jobs for South Africans and attracted R192.6bn in investment,” she said.
IPP office for Africa
Joemat-Pettersson said the IPP office mandate will come to an end in this month and will be reshaped to grow its level of influence in South African and in the broader continent.
“The IPP office is a success story that we would like to duplicate in other countries,” she said. “The reshaping of the office has started in earnest and will have a larger mandate.
“We would like to invite businesses and stakeholders to comment on what it is they appreciated in the office and what we could do better,” she said. “The success story is because we pulled together a sound group of skills, which allowed us to work effectively and efficiently to meet time frames.
“Policy certainty around the programme and integration with other demands has allowed the programme to be sustainable,” she said. “We must build on the success of this innovation, but look at transferring skills and technologies.”
Load shedding is having a severe financial impact on South African food production, according to an expert at energy efficiency firm Energy Partners.
Load shedding is having a severe financial impact on South African food production, according to an expert at energy efficiency firm Energy Partners.
According to Dawie Kriel, the head of heating, ventilation, air conditioning and refrigeration at Energy Partners, this affects not only primary food production, but also post-harvest handling and the retail sector.
“The interrupted electricity supply is costing the local food production industry millions every month and could be depriving South Africa of quality nutrition,” said Kriel.
His comments follow a plea from the South African Poultry Association earlier this month for government assistance to help them guarantee electricity supply to the nation’s biggest abattoirs as almost-daily load shedding is harming the birds’ welfare and creating health risks.
The slaughterhouses, some of which can process as many as 13 000 chickens hourly, can’t rely on generators as they aren’t able to create sufficient power for their needs, said Kevin Lovell, CEO of the poultry industry body.
Lovell told Bloomberg the birds are typically stunned unconscious by electrocution before they are decapitated while hanging upside down.
When power cuts interrupt the process, the birds “have been stunned but they haven’t been killed; they’re hanging upside down and they’re coming back alive”, he told Bloomberg.
“It’s a real problem. And it’s a huge waste problem because everything that stops in the process, sometimes hundreds of tons, has to be cleared. You have to clean and sterilise everything and then you have to dump at a medical waste site.”
Kriel said on Wednesday that the entire supply chain – from primary production through to the consumer – is impacted in one way or another, because farmers are highly dependent on electricity for key processes such as irrigation, livestock care and harvesting.
“The biggest problem for primary production is the uncertainty around the load shedding schedule. It is very difficult to halt production or manufacturing processes once they are in progress,” said Kriel.
“In the dairy industry, for example, a herd of dairy cows and the infrastructure to support milk production run predictably every day according to the animals’ biorhythms. It is not something that can be switched on and off at a moment’s notice.”
This was the same problem for the poultry industry. Lovell said while load shedding followed schedules, it was sometimes imposed at a few minutes’ notice.
Kriel said once fresh milk is in a silo it has to be treated, cooled and transported to a dairy plant for careful processing to ensure that quality and safety are maintained.
“Once in the factory, it needs to be kept at the perfect temperature and then processed through a series of heating and cooling stages to provide the milk, cheese, yoghurt, butter and many other products used daily,” said Kriel.
The cooling plant is a crucial element and a big energy user in the production process. It needs to run 24 hours a day, 365 days per year.
“While solar and wind energy can assist, it is not ideal for this type of load and has to be integrated with a form of standby power generation.”
Kriel pointed out that reliable energy is of equal importance in the post-harvest sector, as the long-term quality and safety of food products depends on accurate temperature management throughout the process.
“If this process is interrupted at any stage, the food product deteriorates in quality and cannot be sold as premium grade or worse, has to be discarded due to food safety concerns. This means food producers are losing valuable income and the country is deprived of quality nutrition,” said Kriel.
Cold chain disruption affects retail sector
Power interruptions also have an impact on the safe handling and storage of perishable foods in the retail sector.
“If the cold chain is disrupted, shelf life is affected and shop owners either have to remove affected products from their shelves or face unhappy customers who return inedible products,” he said.
“Lights, refrigeration, ovens and all other energy intensive elements must be as energy efficient as possible and energy usage must be monitored closely. Once this has been implemented, store owners can invest in standby generation and solar power, especially if they trade mostly during daylight hours,” said Kriel.
Royal College of Art graduate Charlotte Slingsby has developed energy generation system involving sheets of plastic with wave-like filaments.
While the cost of electricity is a constant bugbear in many countries, South Africans face a bigger problem: keeping the lights on. These blackouts prompted Cape Town native Charlotte Slingsby to seek out a solution after her family home was found to be unsuitable for solar panels.
The result was Moya (wind in the Xhosa language), a new energy generation system: sheets of plastic have wave-like filaments attached that capture tiny amounts of wind energy that can then be stored in a battery.
“We need an independent solution for today,” Slingsby said. “You see a city which functions on electricity which just falls apart, from the most basic things like opening a door [or] an electric gate. You can’t even take your car out of the garage.”
She cites serious examples, such as people on life support machines who depend on a reliable electricity supply for survival. In a security-conscious society like South Africa, the shutdown of alarm systems at night can also be an invitation to criminals.
“It is quite terrifying and it is those day to day things that you forget about. Every part of your day changes,” she said.
Moya was developed during a two-year postgraduate course in innovation design engineering that Slingsby recently completed at the Royal College of Art (RCA) and Imperial College London. The system is aimed at accumulating small pieces of energy into a larger mass, in a similar way to drops of rain gathering together to eventually form a stream.
“I thought ‘ow do you come up with a new type of material- one that can accumulate all of those abundant but lower grade forms of energy?’”
The plastic sheets have slivers of bendable filaments that stand up and are moved by gusts of air. The filaments, which are encased in plastic, work using the piezoelectric effect – the ability of some materials to generate a charge in response to pressure. In this case, when the filaments are moved by gusts of wind, tiny pieces of energy are created. For her prototype, Slingsby used a flexible film of polyvinylidene fluoride.
“They have the ability to transform strain or bending energy into electrical energy,” she said.
This energy is then passed on to a capacitor – a device used to store an electrical charge – and then eventually on to a battery. Like the rain over a mountain, “thousands of tiny drops need to be accumulated to have enough energy to bring itself to the rivers and eventually to the sea”.
From tests she has carried out on wind tunnels, Slingsby has calculated that her prototype Moya system can generate about 10% of the energy per sq metre that a solar panel can. But the advantage of her sheets is that they can be installed in areas where solar panels cannot, such as under bridges. “It is reduced in efficiency but it is looking at a new type of material which has the ability to go in far more locations. It is all about accessibility to captured energy.”
One possible location for the panels is on the London underground. “Every tube is stopping and starting all the time and as it stops you can actually line the section of tunnel where it is slowing down, which almost assists the breaking through the added drag, and absorbs this wasted energy,” Slingsby said.
In theory, the sheets can be mounted anywhere, she said, including on the side of a skyscraper, but light would still be able to get through.
It will be some time before the system makes it that far. Slingsby said it could take between five and 10 years – after significant amount of research – to get to a marketable product.
Among the problems she faces is encouraging people to accept another form of energy generation. “What has to be understood is that in the future, whatever energy we are able to absorb freely is actually really valuable and there is going to be lots of different methods with different environments no matter how you look at it,” she said.
Power to the people
The energy crisis which has hit South Africa has sparked often daily blackouts and has hit growth projections for the country. The blackouts are known as “load shedding’, where there is not enough power to cover the whole area resulting in sections being shut off. South Africa’s president, Jacob Zuma, blamed the poor infrastructure on apartheid, saying the system had been built to service only the white population. About 11 million people have power now in South Africa, twice the number in 1994. The problems have also been blamed on poor management and lack of investment.