Three lessons for cities in Denmark’s clean-energy revolution, Jun 30 
60 Minutes On This Bicycle Can Power Your Home For 24 Hours, December 14 
Cities And Regions Moving Towards 100% Renewable Energy, December 8
The co-benefits of community energy, October 8 
Renewable Energy Now Employs 7.7 Million People Worldwide, May 19 
This striking chart shows why solar power will take over the world, April 15 
Energy: Thriving On Five Percent? March 3 
A community solar farm or garden is a solar power installation that accepts capital from and provides output credit and tax benefits to individual and other investors. In some systems you buy individual solar panels which are installed in the farm after your purchase. In others you purchase kW capacity or kWh of production. The farm's power output is credited to investors in proportion to their investment, with adjustments to reflect ongoing changes in capacity, technology, costs and electricity rates. Companies, cooperatives, governments or non-profits operate the farms.
Centralizing the location of solar systems has advantages over residential installation that include:
- Trees, roof size and/or configuration, adjacent buildings, the immediate microclimate and/or other factors which may reduce power output.
- Building codes, zoning restrictions, homeowner association rules and aesthetic concerns.
- Lack of skills and commitment to install and maintain solar systems.
- Expanding participation to include renters and others who are not residential property owners. W
Distributed energy, also district or decentralized energy is generated or stored by a variety of small, grid-connected devices referred to as distributed energy resources (DER) or distributed energy resource systems.
Conventional power stations, such as coal-fired, gas and nuclear powered plants, as well as hydroelectric dams and large-scale solar power stations, are centralized and often require electricity to be transmitted over long distances. By contrast, DER systems are decentralized, modular and more flexible technologies, that are located close to the load they serve, albeit having capacities of only 10 megawatts (MW) or less.
DER systems typically use renewable energy sources, including small hydro, biomass, biogas, solar power, wind power, and geothermal power, and increasingly play an important role for the electric power distribution system. A grid-connected device for electricity storage can also be classified as a DER system, and is often called a distributed energy storage system (DESS). By means of an interface, DER systems can be managed and coordinated within a smart grid. Distributed generation and storage enables collection of energy from many sources and may lower environmental impacts and improve security of supply. W
An energy audit is an inspection, survey and analysis of energy flows for energy conservation in a building, process or system to reduce the amount of energy input into the system without negatively affecting the output(s). An energy audit is the first step in identifying opportunities to reduce energy expense and carbon footprints. W
According to the International Energy Agency, improved energy efficiency in buildings, industrial processes and transportation could reduce the world's energy needs in 2050 by one third, and help control global emissions of greenhouse gases.
Energy efficiency and renewable energy are said to be the twin pillars of sustainable energy policy and are high priorities in the sustainable energy hierarchy. In many countries energy efficiency is also seen to have a national security benefit because it can be used to reduce the level of energy imports from foreign countries and may slow down the rate at which domestic energy resources are depleted. W
Microgeneration is the small-scale generation of heat and electric power by individuals, small businesses and communities to meet their own needs, as alternatives or supplements to traditional centralized grid-connected power. Although this may be motivated by practical considerations, such as unreliable grid power or long distance from the electrical grid, the term is mainly used currently for environmentally conscious approaches that aspire to zero or low-carbon footprints or cost reduction. W
Microgrids are modern, localized, small-scale grids, contrary to the traditional, centralized electricity grid (macrogrid). Microgrids can disconnect from the centralized grid and operate autonomously, strengthen grid resilience and help mitigate grid disturbances. They are typically low-voltage AC grids, often use diesel generators, and are installed by the community they serve. Microgrids increasingly employ a mixture of different distributed energy resources, such as solar hybrid power systems, which reduce the amount of emitted carbon significantly. W
A sustainable community energy system is an integrated approach to supplying a local community with its energy requirements from renewable energy or high-efficiency co-generation energy sources. The approach can be seen as a development of the distributed generation concept.
Such systems are based on a combination of district heating, district cooling, plus 'electricity generation islands' that are interlinked via a private wire electricity system (largely bypassing the normal power grid to cut transmission losses and charges, as well as increasing the robustness of the system). The surplus from one generating island can therefore be used to make up the deficit at another. W