In Part 3A of this series we’ll look at the other common methods of providing grid energy, including some other common pitfalls.
You may have noticed that there is not a lot of information out there on the web about the other popular ways of providing grid energy. That’s understandable, since they’re not really new ideas, and as a result very few people have ever built them.
In the USA, Germany and Great Britain they’re pretty much the only options available to people who want to supply grid energy to their community. The UK’s Community Power purchase agreement, introduced in 2001, replaced the Power Purchase Agreements that had been used previously. It allowed people to buy electricity generated by grid operators like London & North East Energy Company (LENECO) at a fixed price for a set period of time. It’s still possible to use those, and if you’re planning to build one in your area you can get a discount on the installation cost if you use it for less than three years. It’s not something that people often choose to use, however, because it’s not very familiar.
Community Power purchase agreements are like the batteries of grid energy. You buy them, get paid for them, and they provide energy until they’re needed. People do them all over the country, mostly for schools and colleges.
The Battery System
In England and Wales, the Community Power Purchase Agreements are often combined with battery storage. Because school/college campuses are usually not on the grid, their energy needs are usually met by other means. When the grid fails, the battery system kicks in and provides energy until the school/college gets its own energy back. In this way, the system can provide energy for up to thirty days, or half of the school year.
The grid system is usually on standby mode, waiting for the battery system to need energy again. If the grid system goes into standby mode for ten days straight, the battery system kicks in and provides energy for the remaining months.
Not everyone agrees that this is the better way to provide grid energy. Some prefer using a generator to provide energy, and keep the grid system running while the battery system provides backup. This gives students the opportunity to switch energy sources on a semester to semester basis.
When to use which is a matter of individual preference. In a nutshell, if you want reliable grid energy, use a grid tie system. If you want the option to use alternative energy sources, use a grid storage system. The choice depends on the individual, his needs, and his budget.