Well, here they are - the solar panels. In place, just waiting for electricity supplier Innogy to hook up the inverter to the grid. In the meantime, sunny days (like today) come and go and the panels lay there, idle. One day, Innogy will give a date when an installer will come and switch meters, and make the final connection. From then on, electricity bills will become a thing of the past - there will only be a nominal charge (around 40 zlotys/£8 incl. VAT a month) for grid connection.
How does it work? The key thing is to know how many kilowatt hours of energy your house consumes. Polish law on renewable energy sources prevents the selling of power that's surplus to a home's requirements, so if you put too many panels on the roof and over a year you end up producing more electricity than you use, you lose. You give electricity to the grid for free. And if you put up too few panels, you pay the difference between what they produce from the sun and what you have to pull down from the grid, again over a period of a year.
Other than the panels, your house needs two additional bits of kit. One is the inverter, which sits by the junction box, between the grid and all your household appliances. The second is a WiFi-connected smart meter, which gathers data from the panels and informs you (and your electricity supplier) how much power the panels are generating, or if they are not generating, how much power you're pulling down from the grid, so as to work out the balance.
If your installer has done the sums correctly, you will have exactly as many panels as you need. Too many, and you end up sending surplus back to the grid, having paid for the panels and their installation. Too few, and the sum doesn't balance the other way, and you pay for the kilowatt hours that have to be drawn down from the grid to make up the difference.
Here, it's ten panels, facing south-west. Alignment (azimuth) and zenith angle are crucial. On my działka, the roof could not be aligned worse - it's exactly east-west. Optimal is a roof with a south-facing slope. A flat roof is useless too, as the panels need to be angled up towards the sun so that the rays can fall as close as possible to the perpendicular.
The cost of the installation was around 21,500 złotys; half paid upfront, the other half after grid connection. And then comes the magic bit - once hooked up, your energy supplier applies for a 5,000 złotys government grant, which will be paid back directly to me. Plus, you can offset the investment against your tax bill. All in all, we worked out with the installation company, Stilo Energy, that in the case of our house, the investment will be fully paid off in just over six years - assuming the price of electricity doesn't go up over that time - which it will.
The government incentive is a package called Mój Prąd ('My Current') announced in July 2019; the bad news is that it the scheme coming to an end this month. It has been very popular. On my motorbike rides around southern Mazowsze and into Świętokrzyskie and Lubelskie provinces this summer, I could see plenty of rural households that have taken it up. All households consuming between 2kW and 10kW are eligible. In some cases, the panels were installed on rickety old barns that happened to have optimally aligned and angled roofs. Others, having poor roof alignment, have build car ports or other structures that exist primarily so as to have a roof in which panels can be optimally mounded.
Installing photovoltaic panels on an existing roof is called BAPV - Building-Applied Photovoltaics. This is today. The future will be BIPV - Building-Integrated Photovoltaics. Architects designing new houses should already be doing so around solar panels, planning roofs so that the zenith and azimuth angles are optimal for a given latitude, and that the panels fit flush with the roof for aesthetic purposes.
A huge breakthrough will be the eventual replacement - or conjunction of conventional silicon-based panels with perovskite film. The process, invented by Polish scientist Olga Malinkiewicz, takes perovskite - a transparent crystal, which generates electricity when light shines on it, and ink-jet prints it onto rolls of plastic film, many times thinner than a human hair. As you can imagine, this can be stuck onto office windows to turn office buildings into power stations. The Polish company that is commercialising this process is called Saule Technologies, and I hope you will be hearing about it in the future.
If you work in the construction sector (architect, civil engineer, developer, contractor/subcontractor) or in real estate (investor, consultant, agent), pop into this free webinar this Thursday (3 December) to learn more about how BAPV and BIPV will revolutionise our buildings.
This time last year:
Jeziorki's ponds are drying up
[Happy to report the water level's slightly higher today]
This time four years ago:
Jeziorki - second track, second platform
This time five years ago:
Pitshanger Lane wins London's High Street of the Year award
This time seven years ago:
Trouble ahead in Ukraine.
This time ten years ago:
Jeziorki, dawn, winter
This time 13 years ago:
Tuwim's Lokomotywa in English
Interesting post Michael. Funnily enough I heard about Saule Technologies on the BBC Monday night when I couldn't sleep and turned the radio on for an hour.
ReplyDeleteMy own experience of PV solar panels which are optimally aligned. During the summer they produce more energy than can be used so there is export to the grid (and I have a diverter which sends surplus energy to an immersion heater). During the winter and dull days there is precious little surplus. The rest of the time and at night power is taken from the grid. Without being on the UK scheme, which pays for units generated and pays for a deemed export to the grid, the system would take 20+ years to pay for itself, by which time the efficiency of the panels would have dropped and the inverter would likely have been replaced (expensive). With the UK scheme (which is now closed) the payback period is 8-9 years, assuming the inverter lasts. Better than cash on deposit and allows me to polish my green credentials.
ReplyDeleteIn numbers: my system generates about 3MWh per year, mostly during the summer months, I import about 3MWh, mostly at night and during the winter months. It probably saves me 1.2-2.5 MWh of imported energy. Without the generation payments the payback is questionable. You would be better off investing in the shares of the companies making the systems!
Innogy are totally useless. It took them 6 months to hook up a second power line on an office block.
ReplyDeleteThey also tried to sting a friend of mine a penalty for early termination of contract upon sale of a flat completely missing the point that the penalty would ONLY apply to a second flat where contract not terminated.
Oh and try to contact the German head office. They completely ignore messages sent by e-mail and it's impossible to find a tel number for them.
I am curious what your average monthly electricity usage is. My house is about 2100 sq ft (195 sq m) and my average usage us about 380 kWh a month with premium insulation and all LED lights. The cost of solar panels in Colorado is about $16000 before tax credits - makes me want to fly your solar company to the US ! Hopefully Pres Biden makes good on his promise to advance alternative energy soon.
ReplyDelete