PV is cheap

Dr. Frank Dimroth Homepage

If you are buying a 4.83 kWp PV system from e.g. http://kerst-energy.de/ or http://www.photon-solar.de today and add transportation, sales tax and 600 € for electrical connection, you can build your own solar power plant for 6915 € with all European components! Yes, you will have to help with the installation of the modules or combine it with the renovation of your roof. Also you will have some running costs for insurance and repair of components which is in the range of 174 €/year for this system. But then, you will produce 4347 kWh* of green electricity every year with your PV system in Germany.

Now we can play a little bit with the numbers and see what we can do with the solar electricity which comes from the PV system for 25 years without any fuel costs.

Assuming there is no feed-in tariff and you can only use the electricity which is consumed directly in your house. At 4500 kWh/year consumption for a typical family, you can use approx. half of the PV electricity because it is generated at the right time **, the other half is wasted. For the PV electricity which is used, you save today approximately 0.25 €/kWh on your electricity bill. The result after 25 years is: You have paid back the initial investment and have additionally saved 4474 € of electricity cost which is equivalent to a 2% interest rate per year on the initial investment. We can also calculate the electricity cost of the solar electricity which is 20 cent/kWh based on using only half of the generated energy! 2250 kWh/year are additionally available which may be used to charge batteries e.g. in an electric vehicle or for heating your warm water. This electricity is completely free! If you e.g. replace 925 kWh of heat at 0.07 €/kWh gas cost ***, you will increase the interest rate of your capital investment to 2.7% per year. This is all without any subsidies and without any feed-in tariff for the electricity. If you are further able to sell the electricity which is produced in excess of your consumption at a market price of 5 cent/kWh, you will increase the interest rate even further to 2.9 %. If all the electricity which is produced by the PV system is consumed in the end, the average cost per kWh is 10 cent **** and within 20 years you will have saved an equivalent of 20 thousand liters of oil which are otherwise needed to produce the same amount of electricity in a conventional power plant! *****

The message is: solar electricity is no more expensive when consumed locally. Everybody should be able to get a PV module, produce part of his electricity by solar and save money. Small PV systems which are mounted on facades or roofs including micro inverters are on the market starting at 880 € and producing 440 kWh of electricity per year. Other opportunities are to invest into community PV systems with the investment being shared with the neighborhood. It is time to take the energy revolution into your own hands!

Did you know that Europe spends more than a billion € every day for fossil fuel imports? The solar PV system mentioned above can replace an equivalent of 20.000 liters of oil imports by European jobs. It helps further to reduce climate gas emissions. PV companies in Europe are currently under severe market pressure due to worldwide overcapacities and I urge everybody to invest into PV systems which are locally produced. With this you will bring wealth and employment to our countries.

Dr. Frank Dimroth / 26.4.2013

(*) Assuming 900 kWh/kWp which is conservative. Good places in Germany can be up to 1050 kWh/kWp. The PV power in all calculations is assumed to decline 0.2 % per year.

(**) Calculation performed with Excel tool on photovoltaic-web.de which allows to determine the percentage of self-used electricity from a PV system.

(***) taken from my gas heating bill of 2012

(****) Calculations based on my own detailed Excel sheet. Simplified check for everybody to confirm correct order of magnitude: 6915 € invest plus 25 years times 174 € for insurance and maintenance = 11.265 €. Divide this number by 25 years times 4347 kWh = 108.675 kWh and the answer is 10 cent/kWh PV electricity cost if all the energy is used. 20 cent/kWh if only half of it is used.

(*****) Assuming heat value of oil = 10,9 kWh/l, 45 % efficiency for electricity conversion in central power plants.

F. Dimroth, 30.08.2017, Copyright © All Rights Reserved