Dr. John Hollins, past Chair CACOR Board of Directors, considers “Microgrids: renewables and resilience”
Reduce emissions while keeping the lights on – always
For millennia the renewable sources of wind and water have been used to provide intermittently useful energy in small quantities; they still are in the less developed world. For more than a century, however, the main method of delivering electricity in the industrialised world – to homes, commerce, and industry – has been large stations to generate electricity – from hydro, coal, gas, or nuclear fission – with grids of towers and cables operating at high voltages over long distances.
The emerging technologies to exploit the new renewables – solar photovoltaic, wind, and geothermal heat – provide the opportunity to deliver green energy at smaller scale – to a single home, a community, or an industrial estate – in self-contained systems of sources, storage and demands, referred to as microgrids.
The costs of the new renewables are following steeply descending learning curves. The new renewables, however, fluctuate rapidly and in the industrialised world users expect the light to go on the instant the switch is turned. The cost of a system using the new renewables must therefore include the cost of storage. Storage can be on site or through connection to a conventional large grid.
The Manotick microgrid is an example of a microgrid for a single residence. Entrepreneur Dr. Art Hunter1 has built a microgrid incorporating solar photovoltaic panels and a ground-source heat pump as sources, Tesla power walls to store electricity and the ground for storage of heat and cold, careful management of demands for electricity in the residence, and an electric car. This microgrid is connected to a large main line grid, but it depends on that grid only in the depths of the Ontario winter. It exports substantially more electricity to the main line grid during the year than it imports, resulting in income to pay off the capital costs of the microgrid. It no longer uses natural gas for heating or gasoline for regional travel – reducing the emission of carbon dioxide and creating financial savings.
Manotick microgrid: schematic
One swallow does not a summer make.
Microgrids are not a traditional investment in infrastructure for conventional utilities or financial markets. The existing electric power industry was not designed to facilitate the development of microgrids by individuals, communities or corporations. In order to create effective policy and plans for this new sector, there is a clear need for governments to foster dialogue among the financial community, conventional utilities, regulators, and the emerging sector of contractors equipped to build and maintain microgrids. This need should be turned into an opportunity and be on the agenda of political parties and candidates:
- to reduce emissions,
- to develop resilience, and
- to accelerate the creation of jobs in an emerging sector – to more than replace jobs lost as conventional energy winds down.