Energy prices rise

If you take inflation into account, energy since World War I is cheaper than it ever has been. Gasoline is about the same price as it was a hundred years ago (about a dollar a litre, adjusted for inflation) and all energy is much cheaper than it has been before 1900. Gasoline was cheaper between about 1900 and 2000 or so.

Fortunately technology gets more efficient with time. Compared to the latest and greatest computers, an 80386 just sits there and wastes electricity.

Heating your home is the biggest part of your home energy budget, and your domestic hot water is second-biggest. Cooking and lighting are relatively small slivers.

For example:

• a house built between about 1950 and 1985 or so will have a home heating budget of $2000 - $3000 per year.
• Your computer's power supply uses perhaps 100W -- to be generous, let's say 200W (it's rated for more but it doesn't use all of it.) That's 4.8kWh/day or about 1800kWh/year, at 0.15$/kWh = well under $300/year. Your laptop will use a tiny fraction of that.

Home Study

• Google for "historical energy costs" or "history of energy" to confirm the numbers here
• Put an AC ammeter on your desktop system to find out exactly how many watts it's using.