Posted: 12 March 2014
SOLAR POWER companies say that GRID TIED Solar Power systems are a great investment, you decide ?? Its a great investment if its for a commercial business, or an OFF GRID domestic or the system fits to your daily usage in the household.
My belief is this, on average a householder uses anywhere from 300w to 800w per hour(.5kw average) to maintain the running of fridges and freezers etc during the day between the hours of between 8am - 5pm POWER usage does not vary that much whether your at work or not during the day...the average installed domestic solar power system is around 1.0 - 2.0kw (1.5kw average), so for the sake of the discussion lets use a 1.5kw system to help with this analysis.
Lets assume your SOLAR POWER system will possibly generate 1.5kw of power per hour between 9-4, less your house usage of .5kw per hour, so 1kw per hour is exported to the grid(7kw/hrs per day), you may on average get 10c per kw paid back from your power supplier, your daily profit maybe $.70 x 30 days = $21 per month x 12 months = $252, divided by the system cost of $7000.00 = 27 years payback.
Now the good stuff, when you use all the power the system creates during daylight hours, and do not export anything at all to the grid, it all changes for the better, much much better.
The payback rate is then based on the cost per kw you pay from your power supplier, which say is on average .28c per kw, x that by 7kw/hours produced per day and used in the property..= $1.96 per day, x 30 days a month = $59 x 12 months = $708.00..now divide your $7000 system cost by $708 and your payback is less than 10 years inline of where it should be with todays prices.
It's a no brainer:
It's obvious, it's a great investment, when you do it right.