In 2013 we installed a grid connected PV system to cover our own power consumption, and is thus an important step forward towards the goal of becoming 100% supplied by renewable energy, and as far as possible, self-sufficient. We already have all our transport with cars covered with pure plant oil (PPO, rape seed oil or used cooking oil) since 1999, and all heating is covered by fire wood from own forest. Soon we will install also a solar hot water installation to cover the hot water demand in the summer season.

The solar panels are installed on our workshop building, covers 60m2 and has a capacity of 9.360 Wp.

We have installed extra capacity to compensate for a low roof pitch of only 20°, and because we consume more power than average - approx. 8000 kWh/year.

The PV system is connected to the grid internally in our house installation without a separate energy meter. When the power production is larger than our demand, our energy meter automatically counts the power which runs backwards and is fed into the grid. And when the power production is less than the demand we buy from the grid as usual. As long as the power production/year do not exceed the consumption/year, the price for sold and bought power is the same. If the power production exceeds our yearly consumption, we will only get a low price for the excess power(~8 €ct/kWh). Therefor the aim is just to balance the yearly production with the yearly consumption. The Danish regulation for this kind of grid connected Renewable Energy installation allows a maximum power production of 6kWp (the regulation has been change for PV installation later on, because it became too popular, which led to ~80.000 new installations in a very short period of time)

The output from the inverter has been limited to 6.000Wp due to special regulations for this kind of Renewable Energy installation.

We have installed a 8kWp inverter to match the capacity of the panels, but due to the regulation we have limited the power output to max 6.000Wp by software settings. Therefore, the power curve flattens out in the sunny hours around noon, and some potential energy is not harvested.  On the other hand, the system can produce more power in the mornings and evenings, as well as spring and fall, compared to a "standard" installation with only 6.000Wp capacity on the panels.

Performance on a very sunny but still a cool summer day - a total of 63,3 kWh

Performance on a good spring day - a total of 42.6 kWh


System data:

PV Panels : 36 pcs. Q-CELLS, Q.PEAK G2 260W, total 9.360Wp, 60m2, installed in 2 strings on the workshop building
Roof pitch : 20° S
Inverter: : Danfoss TLX Pro + 8.0k with software restriction to max. 6000W AC output.
Design : Dajolka.dk
Installation : Dajolka.dk & Egens El
Investment (nov 2012) : 11.700 EUR excl. VAT. + Own labor for engineering, procurement and installation
Commissioning : 22/7 2013
Production : Our aim was to produce min. 8.000kWh/year. Production 1st year was 8.889 kWh, and 2nd year 8.573 kWh.
  Se details for production below.

GPS-coordinates        :   57.203885, 10.326947

The chart shows the production for each month during for the first 2 years.

You can follow the production from our plant on the Danfoss CLX portal, where production figures are uploaded each hour.

See production data from DAJOLKA´s PV system

Yearly statement from the utility company

First annual statement from the utility company with negative consumption

Annual statement of the consumption