There is now solar powered electricity at pointReturn and I thought it would be useful to set out how I think about power and energy and what was the process by which I finally selected what I did.

The energy needs of a self-sufficient campus must be met from a basket of sources, each of which is ideal for one area of use- water pumping, lighting, power tools, farm work, cooking, electronics, and transportation. The broad plan for pointReturn, to be realised over the coming years is as follows:

1. Water pumping: windmill, solar electric
2. Lighting: solar electric
3. Power tools: premium grade solar electricity
4. Electronics: premium grade solar electricity
5. Cooking: firewood, biogas
6. Farm work: animal, tree oils based biofuel
7. Transportation: electric and tree oils based biofuel

The above list of energy needs and sources is in the order they are likely to be realised, and as I write the list has been realised up to step 4. The list is also meant to encourage finer thinking about our energy needs. Not all needs require electricity; of them that do, not all need premium grade electricity.

At the risk of lecturing the technically adept reader, let me go through this quick primer. Wind and solar chargers store the power they generate in batteries. It is in the form of direct current or DC. DC is good enough for lighting, heating and some water pumps. We need alternating current at 220 volts 50 hertz - [AC 220v 50Hz] for many appliances. There is a finer division again. The 50 Hz represents the number of times the current alternates in a second, and this is represented as a sine wave. Now this sine wave can be pure or impure [-the correct terminology is - ’square wave’].

We need pure sine wave AC 220v 50Hz for fine electronics like computers, some power tools and video players. I call this ‘premium grade electricity’. We may not need a lot of this but we do need some. With the ‘quality’ of power out of the way, we need to think ‘quantity’ before we can properly size the power plant. One thing not always stressed in self-sufficiency projects is the role that moderation plays; we can never be self-sufficient without moderating our needs and habits. ‘Comfort’ is attained through doing with less.

 Viewed 921 times by 273 viewers

Pages: 1 2 3