Developments regarding the future smart grid in the U.S. are expanding rapidly. We believe that any plans for the future grid, if it’s worthy of being called “smart,” should integrate micro power grids into the equation.
There are relatively few who are aware of micro power grids and their growing importance in meeting our energy needs. This GridWatch Spotlight is intended to increase the awareness of this exciting and important element in the power grid of the future.
What are Micro Power Grids?
Micro power grids involve the concept of microgeneration, which refers to the small-to-medium scale generation of power (usually heat or electrical) especially through the use of low-carbon and renewable energy sources and technologies, to meet the needs of users, including individuals, businesses, schools, hospitals, or even small communities.
Although micro power grids may imply the concept of the distribution of power over a network, there is no reason to exclude the individual home or business as a very localized network and, thus, a micro grid.
The Future is Now
In 2009, over 100 companies were collectively provided about $8 billion to develop a new, smart national power grid system for the U.S. While the current grid is largely centralized, the expectation is that micro grids will become fully integrated into the larger grid network.
Locally-generated power on a small scale is nothing new. Individuals and businesses have been implementing solutions to meet their own energy needs at the local level for years. Micro grid technology isn’t futuristic. It exists today. On the rooftops of houses and other buildings, and as part small communities around the nation.
Since the 1970s, homeowners have increasingly sought to generate part or all of their electrical power and heating needs. The “back-to-the-land” era was a part of the trend. During the past few years, many businesses and a few small communities have been converting to alternative local power systems, in some cases as small networks of self-generating power systems.
Such micro grids have saved consumers money, supported the use of renewable and cleaner energy, and achieved some measure of independence from outside energy supplies. On a national scale, isn’t this precisely what many in the U.S. have been claiming is needed, especially with respect to oil?
Fortunately, it does appear that at least some of the nation’s energy planners and policy makers have started to pay attention to the off-grid and micro grid communities. Recently, one Senator recently introduced a bill in Congress:
“To increase the quantity of solar photovoltaic electricity by providing rebates for the purchase and installation of an additional 10,000,000 solar roofs and additional solar water heating systems with a cumulative capacity of 10,000,000 gallons by 2019.”
Technologies for Micro Grids
The technologies commonly employed in micro power grids come in a variety of forms. These include solar photovoltaic and heating systems, wind and water mills, fuel cells, biomass, combined heat and power (CHP) systems, and others.
For example:
- Photovoltaics convert sunlight into electricity. Best where electricity use matches the times of sunshine or where a local supply of electricity is not readily available.
- Wind turbines convert wind into electricity. Best in places with a relatively constant and sufficient wind supply. The electricity generated is dependent on the wind, which may not be sufficient for a given business or network. Match the electricity demand profile of your building. The electricity generated by a wind turbine generally increases with wind speed, size of the blades, height above the ground, and distance from other structures.
- CHP units capture heat from systems that generate electricity by burning fossil fuels. Although CHP systems burn fuel and release carbon dioxide, their efficiency can ultimately help reduce greenhouse gases in comparison with distant fossil-fuel-powered electricity generation that typically wastes the heat produced as a byproduct, not to mention the electrical energy lost through the transmission network. CHP is particularly useful where the additional heat as a byproduct can be usefully applied. This can be difficult during hot weather.
- Burning biomass. Although this process does not consume fossil fuels, it does release carbon dioxide. Biomass boilers typically require significant space and frequent maintenance. They require ample time to heat up and cool down. Best when there is a plentiful supply of fuel.
- Solar water heating is used to pre-heat water prior to being heated to higher, necessary levels. Most effective during times of sunshine since it can be difficult to store heat over long periods of time.
- Ground Source Heat Pumps are able to generate several times as much heat as the electrical energy required to operate them. A ground source heat pump extracts heat out of the ground by circulating water through pipes located in the ground.
Going Local
In contrast to the centralized structure of the national power grid system, micro power grids are based on the concept of local. There are some who argue that a sustainable power grid must be decentralized. When applied to the power grid, sustainable solutions will require that we address economy, ecology and energy on a local scale, important issues that have been relatively unknown to many in the U.S. today.
This self-generated energy is typically connected to the local electrical utility grid so that any surplus power is fed back into the grid and credited against the user’s account for use at a later time, and at the same time, capturing much of the heat otherwise wasted at a grid’s centralized power plant. When multiple numbers of these self-generation systems are put together in a network, then a micro-grid is created, thereby eliminating dependency on the ever-increasing costs and unreliability of grid power and replacing it with electricity and heat produced on-site at a home, business, school, hospital or any other building in the network.
Micro Grid Advantages
Micro grids provide a number of important advantages over large-scale centralized approaches to power generation and distribution. Here are a few examples:
- less expensive to operate
- energy is distributed more efficiently (no energy loss due to transmission)
- typically uses renewable, cleaner energy
- supports the concerns, interests and businesses of the local community
- better able to manage local power loads and requirements
- reliability is typically higher
- can be used as a backup (for both the micro power generator and the larger network) when the larger grid fails
The Status of Micro Power Grids in the U.S.
While energy policies and laws differ from state to state, some power companies will pay part of the cost of micro power grids in the areas they serve. A good summary of financial incentive programs for individual and businesses regarding the use of renewable energy is provided here.
In addition, some countries, including the U.S., already have laws that allow the selling of electricity from micro power grids to the national grid. So, while there is significant room for improving government support for micro power grids, there is some indication that progress is being made.
Here at GridWatch, we will be keeping an eye on micro power grids and their integration into the smart grid of the future, and reporting on it as it develops.
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I fully endorse these ideas. Not only do they do away with a large proportion of losses through the grid, but also renders the “grid of micro-grids” more resilient to failures, potential attacks and extraordinary natural causes such as sun storms, etc..
I wish our politicians in Ontario would have the same wisdom!