Harvest your own roof for 8 years : Roof restoration

PV as an integral part of the design: "form follows function"

When we designed our Plushuis in 2009, we took a very close look at the passive house principles. That is, a compact design with as much glass as possible facing south, and as little as possible facing north. Actually, we wanted a house with a flat roof. This gives as much content as possible with the least possible use of building materials. You can also "play" on a flat roof with the orientation of the panels.

But we had counted well outside the Spatial Quality Committee! This committee is popularly known as the "Welstand" and did not want to allow a flat Roof restoration house here. You should know that in this street that is called the Rietveldlaan (according to the architect) there were already 2 houses with a flat roof. One as a copy of the iconic Rietveld-Schröder House. The other as the secretary of the Welstand unambiguously expressed it "with the cheapest MBI vowels they have forgotten to plaster".Unfortunately, our idea of ​​plastering the entire house white could not get the committee's approval either. "All houses here have bricks, so your house will get that too, mister Van Everdingen." 

 

Because this stamp plan had been paused by the Council of State for 2 years, we took everything for granted and adjusted the plan accordingly.  
So that is why it has become a gable Roof restoration with glued stone strips for € 9000 on the prefabricated HSB walls. Fortunately, this was already done in the factory.

The assignment to our architect was not yet "design a house that fits exactly 9724 Wp of panels." When we designed the Plushuis (2009), we assumed 2 rows of 13 panels as roof panels. With the panels available at the time, this would give approximately 6240 wp of power. Then we would not be using a substantial amount of the SDE subsidy (see below)! And we would not be able to squeeze the maximum out of the roof surface, a piece of roof would remain unused. By increasing the roof miter cuts by approx. 10 cm. all of a sudden 3 rows of 13 panels could be added, that would be 10,080 wp. With that we would easily generate the 9724 kWh / yr. Unfortunately, the German prefab builder no longer wanted to give a warranty of no less than 30 years (!!) on the entire house if we had a Dutch supplier drill through the roof foil to install the Roof restoration system. We chose eggs for our money and opted for a roofing system. The adage "Form follows function" is literally taken here: Making the best possible use of the roof of every energy-positive Plushuis is a crucial part of the entire design process.   

SDE subsidy

In 2008 and 2009 I applied for an SDE subsidy, both of which were awarded. A 15-year fee for every kWh produced (which you can use for 100% yourself) is a nice incentive. The award felt like a lottery ticket at the time. In recent years, this SDE subsidy has only been available for connections larger than 3 x 80A.

In 2008 I applied for a SDE subsidy for the maximum possible 2924 kWh / yr in production, and in 2009 I applied for a gamble of 6800 kWh / yr. On the gamble because there was a building plot, but no idea how much generating capacity would fit on the house. To fully "milk" this SDE subsidy for 9724 kWh / yr, based on 1000 kWh / kWp, approximately 9724 Wp of generating capacity was required. 

System

choices of the installation An extensive article 1) has been posted about the run-up, the choices etc. of this installation on the unsurpassed site of Polder-PV .We absolutely did not want "Chinese junk panels" on our Roof restoration. And of course we wanted to make the most of our SDE subsidies. Finally we ended up at Zon & Co.

They supplied us with this installation:

42 panels Aleo-S79: Monocrystalline, full-black, made in Germany (the latter was an important selection criterion) of 240 Wp, with a power tolerance of + 5%. The panels are located on a roof slope of 30º to the south. 

2 inverters: SMA Sunny Tripower STP8000TL-10 and an SMA Sunny Boy SB 3000TL-21 (also made in Germany ). These hang in a cool basement, directly under the meter cupboard.

The panels that are least shaded hang in 2 strings of 6 panels each on 1 MPP tracker of the small 1-phase inverter. The other 30 panels are also in 2 strings each on an MPP tracker of the large 3-phase inverter.  Since 2017, the flat roof of the garage has 6 old Sharp panels (from 2005) of 125 Wp each on 3 Gridfit inverters. Until July 4, 2020, these added approx. 1460 kWh to the more than approx. 80,000 kWh of the large installation.