Nov 08 2007
Part of building a home with renewable energy systems, such as solar panels, is deciding whether or not it should be connected to the electrical grid. There are numerous considerations — namely practical, economic, and environmental –involved in making your decision.
However, this choice can be difficult without a good understanding of what the terms grid-tied and off-grid actually mean. A grid-tied home is connected to power lines which transmit electricity to the home, mainly from power plants, yet can also produce power on-site using renewable energy systems. An off-grid home is not connected to power lines and, therefore, it relies solely on renewable energy systems to produce electricity and storage systems such as batteries to mediate the supply.
As we examine the practical implementation, cost, and environmental impact of each, we’ll see how being connected to the electrical grid is typically more beneficial than being completely detached from the predictable source of electricity and storage it provides.
A good starting point when deciding to be on- or off-grid is whether or not it is practical for your specific situation. If you are planning to build in a remote area, it may not be practical to be grid-tied given that costs for running power lines increase the farther away your home is from the electrical grid. If this is the case, and there is no constant source of electricity available to you, the only power available would be the amount of energy your home’s renewable energy systems produce. A battery system can store any energy that is not being immediately used, but the off-grid home remains limited by the amount of power it produces.
Being on the grid eliminates the need for a battery system and is a typical installation matter for most electricians. Being grid-tied can help you manage unforeseen energy needs more easily than in off-grid homes, and therefore it allows for a more lenient approach to energy use. It is similar to having overdraft protection at a bank. If you choose to, you can “pay back” energy to the grid at your convenience.
Cost is another important factor in deciding whether to be grid-tied or off-grid. The initial cost of the battery system and its associated wiring and components to store your energy can be thousands of dollars. Batteries also have a far shorter lifespan than solar panels and will need to be replaced over time.
In comparison, being grid-tied is relatively inexpensive. In most states, grid-tying enables you to net meter, in which your meter spins backwards (crediting you) for the energy you produce, and forwards (debiting you) for the energy you draw. On the very sunny days when you are producing the most power, you keep all the credits you produce, whereas with an off-grid, battery system, the battery’s capacity caps the “credits” you could accumulate. There are no maintenance fees associated with grid connection, just a small minimum charge of around $10 each month from the power company to maintain the connection.
Finally, choosing whether or not to be connected to the grid has an impact on the environment and should be a part of your decision. The choice details can be complicated, however, there are a few basic points to consider.
The materials used in the construction of most batteries are highly toxic and not particularly easy to dispose of or recycle; however, the recycling process continues to improve slowly as new research brings discoveries into the mainstream. Using the grid, which traditionally generates power from fossil fuels , can have very little net environmental impact if you produce the same amount of energy that you use.
Being grid-connected is standard for most homes built today. If you are planning to build a home that uses renewable energy systems, being grid-tied is still the most common and probably the best choice due to the security of constant grid energy, smaller up front costs, and minimal environmental impact.