In light of a severe winter with prolonged power outages in many parts of the country, and a financial crisis that has all the makin’s of a prolonged contraction, many of our customers are asking about back-up power. Straight grid-tied solar and wind systems are extremely elegant in their operation. They take the energy from a renewable source and turn it into electricity that can be used in your home or pushed out into the grid. When the sun is shining you can run your meter backwards and build up a credit. When the sun goes down you use that credit to operate your appliances and lights – the grid is your battery. But, in the event of a power outage, your renewable generating source has to shut down in order to insure the safety of the power line workers. The sun is out, the solar panels are ready to send their electrons into use, but the system must wait for the grid to come back before it can begin generating. It won’t work without the grid. This is where back-up systems come in. For years now Hire has designed and installed high quality off grid and back-up power systems. These come in all shapes and sizes with three basic types:
- 1) Prime mover (petroleum powered generator),
- 2) battery back-up and
- 3) grid tie w/ battery back-up.
A back-up generator is often the most cost effective way to provide electricity in the event of a power outage. All you have to do is buy fuel for it and listen to it go. Generators come in two basic types: Portable that you would plug extension cords into, and fixed that would be permanently tied into your electrical system. The main concern w/ both types is to insure that you don’t push power onto the grid and harm (potentially kill) any linemen. This is accomplished with a professionally installed transfer switch. Great article by WA L&I about transfer switches to tie in a generator.
An inverter system tied to multiple energy sources (solar, wind, grid, generator), with batteries and a way for you to access the power – either tied into your primary electrical system through a transfer switch or equipped with receptacles to plug your critical loads into. When the power goes out this system provides power based on the rating of the inverter, size of the battery bank and availability of your alternate source of charging.
Grid-tie with Battery Back-Up (link to Blog post showing a recently installed system). This system affords the best of both worlds for back-up power. Your system is connected to the grid and when you are producing more than you need your power can flow back to the grid. The grid can keep the batteries charged when there is no sun or wind. This system adds some extra cost and maintenance but can be an excellent option for many.