According to CE Delft’s report, The Potential of Energy Cities in the European Union, by 2050 almost half of all European Union households could help to produce renewable energy, with offgrid communities contributing 37% of this number.
These smaller, decentralised systems operate independently of the main grid and offer greater stability and independence than traditional offsite power stations, giving consumers agency over their own energy needs in the process.
Power Technology looks at some of the most innovative examples of communities who have taken power production into their own hands.
SIDE systems: the Netherlands
Over the past year, four Smart Integrated Decentralised Energy (SIDE) system projects have been set up in Amsterdam, namely the Aardehuizen, De Ceuvel, Schoonchip and Republica Papaverweg.
Microgrids are used at each site to connect the town to a localised energy network, while renewable technology such as rooftop solar panels, heat pumps and storage batteries are used to generate electricity, which is then shared between households.
A smart management technology is also deployed to balance supply and demand, sending surplus energy to batteries or to other components in need of power.
A study commissioned by the Dutch Ministry of Economic Affairs and the Netherlands Enterprise Agency is monitoring the performance of each site, with the aim of discerning the most effective SIDE systems.
If replicated on a large enough scale, SIDE systems could be key to helping the Netherlands achieve its climate target of reducing carbon emissions by 80%-90% by 2050.
The Brooklyn microgrid: New York
Fears over grid stability have begun to pick up in the US over recent years, with natural disasters becoming increasingly common and often resulting in blackouts. In response, researchers across the country are turning to the more stable alternative of microgrids.
One such example is the Brooklyn microgrid, set up by LO3 Energy in collaboration with Siemens. Initiated in early 2015, the project is one of the first to use blockchain in an energy transaction, allowing consumers to sell excess energy to their neighbours in a peer-to-peer transaction.
Such a system differs from the traditional set up that allowed residents with photovoltaic panels to sell surplus energy back to utilities, but which could never make a profit from it, instead simply having money deducted from their bills.
With utility firms taken out of the equation, consumers were able to gain both financial and energy benefits. The microgrid control system also allows the energy generated to be redirected to hospitals, shelters and community centres in instances of blackouts.
Higashi Matsushima: Japan
Similar to Brooklyn, the establishment of the Higashi Matsushima microgrid was motivated by fears over natural disasters destabilising the existing energy system.
The country’s National Resilience Programme was set up following the 2011 earthquake, intended to design and install backup systems to be used in instances of main network failure. A number of offgrid communities have sprung up as a result of the scheme, with Higashi Matsushima being the first.
Higashi Matsushima City Smart Disaster Prevention Eco Town officially opened in June 2016, aided by funding from the Ministry of Environment. If the main grid network fails, the town’s microgrid is able to supply power for several hours, either to the town itself or redirected to public facilities such as hospitals and schools.
The city plans to become a net zero energy metropolis by 2022 and aims to produce 120% of power demand by 2026.
Isle of Eigg offgrid system: Scotland
In 2008, the Isle of Eigg became the world’s first community to launch an offgrid electric system powered solely by wind, water and solar.
Prior to the launch, the island’s inhabitants, which number just under 100, relied on diesel generators that were unreliable and expensive, as well as carbon-intensive. The decentralised system, by contrast, offered 24-hour power to residents for the first time.
The site includes a 50kW photovoltaic array, three hydroelectric generators, and four 6kW wind turbines. On average, the island runs on 90%-95% renewable energy, and on overcast or calm days, two 70kW backup generators are used to add power and charge the battery bank. Power is distributed via 11km of underground cable that forms an electricity grid.
The largest hydroelectric generator, situated on the north side of the island behind Laig Bay, can produce up to 100kW, while the two smaller hydros on the island’s south side produce 5kW-6kW each.
The £1.66m project was largely financed by the European Union’s European Regional Development Fund, as well as by national bodies and contributions from the islanders.
Borrego Springs demonstration microgrid: California
The town of Borrego Springs, home to 3,400 people, is located around 90 miles east of San Diego and at the furthest end of a gas and electric transmission line. High winds, forest fires and flash floods, in addition to its distance from the transmission line’s source, means the town is subject to frequent power outages.
Following a particularly bad wildfire in 2007, which took down the transmission line, San Diego Gas & Electric received an $8 m grant from the US Department of Energy to build a demonstration microgrid in the neighbourhood.
A first of its kind in the area, the Borrego Springs microgrid uses smart grid technology that can respond to environmental and system conditions. It can also be disconnected from the main grid during emergencies, supplying energy to the community via onsite resources.
In 2015, the California Energy Commission awarded San Diego Gas & Electric a $5m grant to connect it with a nearby 26MW NRG solar farm, making it the largest microgrid in the country that operates solely on renewable energy.
Carbon-negative Samsø: Denmark
The self-sufficient island of Samsø in Denmark was established in 1997, after it won a competition asking local communities and islands to design and present viable plans for a complete transition to energy independence through the use of renewables.
Now, Samsø is carbon-negative, generating more energy from renewable sources than it consumes. To compensate for carbon emitted from the transport sector, ten offshore and 11 onshore wind turbines were constructed, with a total generation capacity of 34MW.
The carbon footprint of residents now stands at negative 12 tonnes per person per year, with the Danish average being 6.2 tonnes.
The island’s long-term aim is to becoming completely fossil fuel-free by 2030, replacing all oil, gas and coal with renewable alternatives.