How much energy does the ISL solar system save?
All solar systems save far more energy in use than in their manufacture and operation. The actual amount of energy saved depends on the household hot water usage, but is generally between 30 and 70% of the total hot water consumption. The financial saving will depend on the cost of fuel and efficiency of the existing boiler. Tests by the Netherlands building research organization TNO have shown that a single panel system should provide 4 GJ [giga joules] per year or 1112 kWh [kilo watt hours] under standard circumstances, at the taps (much more from the collector into the cylinder). Of course the more panels that are fitted the more energy that will be saved. Of course with no electricity running costs or antifreeze to top up, there are no running costs to offset against these savings.
