all about electric SOLAR systems sizing

PART 3

See also: Part 1, 2, 4

Sizing your PV system

Most residential PV solar systems are in the 1 kW/year to 2 kW/year (kilowatt) range... But that's a bad option. These are very small systems; they aren't designed to meed the electricity needs of average households.

You should aim a lot more.

Consider installing a PV system designed to meet all your electricity needs - as long as you have an energy efficient home, with an efficient lighting system and energy-efficient appliances and electronics.

How large should the photovoltaic system be?

The average American household electricity consumption amounts to about 12,000 Kwh per year. But you can reduce this consumption to 5,000 Kwh or less in new construction, through energy efficiency.

In other words: a 4 kW or a 5 kW PV system can meet all the electricity needs of energy efficient homes in southern U.S. states, but you may need a 6 or a 7 kW photovoltaic system (in modest-sized and energy efficient homes) in other North American climate zones.

Photovoltaic arrays of this size will also meet the average home electricity consumption in countries such as Australia (average system:: 7,200 kWh/year), France: (6,300 kWh/year), UK: (4,600 kWh/year), Germany (3,500 kWh/year). Brazil and Mexico: (1,800 kWh/year): source : World Energy Council.

Obviously, in the end, all depends on factors such as the 1) size of the house, its 2) energy efficiency, 3) local solar radiation and 4) solar orientation and 5) installation issues.

Selling power to the grid?

It seems a good idea: what about installing a large PV residential system, expressly intended to produce more electricity than required by your house, in order to sell it to the local electric company?

Well. It seems a good idea, but it may not be feasible - even if you have the space to install a large system.

In most states (or countries) utilities are compelled to offer two-way electricity meters to people with solar power or other renewable systems, but - typically - regulations do not compel the utilities to buy excess power from households.

It’s more than just a regulatory problem; it’s also a matter of prices and competitiveness: donot forget that you are producing electricity at a small scale, in a location that may not have the best solar potential – and that affects your competitiveness.

It may not be advantageous for the utility to offer you a decent price: because they may be dealing with storage issues (electricity can’t be stored in large quantities, or efficiently), or because the utility can produce cheaper electricity (by producing it at a larger scale, or in locations with better resources than yours, or using other means), or because there may exist other players able to produce electricity at lower prices.

 

See also: Part 1, 2, 4

For more information:
Before Installing a PV System
Prices PV Systems
Solar PV Systems

 

 

 

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