Photo­vol­ta­ic from the bank (no real be­ne­fit for me)

A while ago I got a mail from my bank. They of­fer to fund a photo­vol­ta­ic sys­tem on my house with a spe­cial of­fer. They give a cred­it upto a spe­cif­ic amount if I use it to in­stall a photo­vol­ta­ic sys­tem, and to pay it back I just have to give them the com­plete amount of money which I get from the power com­pany when the photo­vol­ta­ic sys­tem is pro­du­cing power (the state re­quires the power com­pany to pay a spe­cif­ic amount of money – fixed dur­ing 20 years – for each kW/​h). They also of­fer that a spe­cial­ist vis­its me to ex­plain the photo­vol­ta­ic stuff and cal­cu­late if all the phys­ic­al con­straints for such an in­stall­a­tion are OK.

At first this sounds nice, but I do not trust the words of some ran­dom per­son which wants to get money from me. So I had a deep­er look at it.

The roof of my house is still OK, but in some years (maybe 3 – 5) it has to be changed (at least partly). The roof  is already 30 years old, so this is OK. If I would in­stall a photo­vol­ta­ic sys­tem now, it would have to be re­moved and re­in­stalled when the roof is changed. If the sys­tem is fin­anced by the bank, this has to be done by an of­fi­cial spe­cial­ist (in­stead of let­ting a good friend with ex­per­i­ence do­ing it in ex­change of my work­force for some renov­a­tion pro­ject at his house). This means it would be cheap­er if I change the roof be­fore the photo­vol­ta­ic sys­tem is in­stalled. I do not have the money to do this com­pletely out of my pock­et, so the bank has to fin­ance this.

Let­ting the cost of the roof aside (which has to be done “soon” any­way), the in­ter­est­ing part now is what do I get when the bank is com­pletely fin­an­cing the photo­vol­ta­ic sys­tem (maybe parts of the elec­tric­al in­stall­a­tion need to get up­dated, as they are 30 years old too). I have to take in­to ac­count taxes, what needs to be paid back to the bank, what I have to pay for the power, and what I have when everything is paid back.

If the photo­vol­ta­ic sys­tem is fin­anced com­pletely by the bank, the typ­ic­al cal­cu­la­tion is that it takes about 20 years to pay back everything. This as­sumes I only give to the bank the amount of money I get from the power com­pany for the power of the photo­vol­ta­ic sys­tem. So ba­sic­ally the photo­vol­ta­ic sys­tem pays it­self. This sounds great, the prob­lem is that a rough es­tim­a­tion of the life­time of a photo­vol­ta­ic sys­tem is 20 years (and after 10 years you may have to change the AC con­vert­er). The war­ranty on photo­vol­ta­ic ele­ments here is 2 years, so far I have not seen any of­fer where they ex­tend it much (some­how it is hard to find some good pages for private cus­tom­ers, most of the pages I see are either light on info, or tar­get com­mer­cial cus­tom­ers). This is not even re­motely in the range of 20 years. So after it paid back it­self to the bank, it may be broken. And dur­ing those 20 years, I still have to pay my com­plete power bill.

There is also a tax point of view to take in­to ac­count. Luck­ily a friend of my sis­ter is do­ing some tax con­sult­ing for private tax is­sues. The tax stuff in­volved here is about com­pany taxes (you are re­quired to open a com­pany when you in­stall a photo­vol­ta­ic sys­tem here). This is not spe­cially in the area where she is work­ing in, but I as­sumed she should know enough about the ba­sics, that I can get at least an over­view. I got even more than that. When I talked to her about it, she told me they cal­cu­lated a sim­il­ar of­fer for their house re­cently. She as­sumed a photo­vol­ta­ic in­stall­a­tion of 20 T€ and that the bank is fin­an­cing it com­pletely. The roof of their house does not have the same char­ac­ter­ist­ics than my house, but as the photo­vol­ta­ic spe­cial­ists cal­cu­late with rough peak sun­shine hours any­way, it gives me a rough over­view. The good part is, that you do not lose money this way, but you have to pay the tax dir­ectly (even if I give all the money from the power com­pany to the bank), you start to earn money near the end of the 20 years.

Ac­cord­ing to her cal­cu­la­tions you will have earned 6 T€ after 20 years, when the photo­vol­ta­ic sys­tem paid it­self back to the bank and you had to pay the taxes each month/​year/​whatever. This as­sumes that the peak sun­shine hours are not get­ting worse, and that the ef­fi­ciency of the photo­vol­ta­ic sys­tem stays at roughly the same level dur­ing the 20 years. Now let us cal­cu­late the amount of money per month and per year you gain when you do this:

6000/20 = 300 €/​year

300/12 = 25 €/​month

So for 25 €/​month I have to in­vest my time in­to tak­ing care about the tax stuff, have to take care about the photo­vol­ta­ic sys­tem (clean­ing, and man­age­ment stuff in case some­thing breaks be­cause of bad weath­er or nor­mal us­age), have to pay ex­tra money when some­thing has to be done to the roof, and so on. And when everything is fin­ished after 20 years, the photo­vol­ta­ic sys­tem may be fin­ished too (and the rate of money the power com­pany has to pay for each kW/​h then is not known, in case the sys­tem still works good then). If it is in a state where I have to re­move or re­place it, I also have to pay the cost of re­mov­ing it. And I need to get to­geth­er enough money to get a new roof now.

Now this of­fer does not sound so good any­more (re­mem­ber, I also have to pay the power I con­sume dur­ing this time). To me it looks like only the bank and the com­pany in­stalling the sys­tem will be­ne­fit from it, and I have to take care about all the un­pleas­ant things.

There is for sure an eco­lo­gic­al as­pect to think about here. It sounds great to pro­duce green en­ergy (I do not know how much CO2 is pro­duced dur­ing the pro­duc­tion of the photo­vol­ta­ic sys­tem, and if it will pro­duce enough en­ergy to com­pensate this), and I would do it dir­ectly if I would see a sane re­turn of in­vest­ment, but this of­fer does not look sane in my cur­rent situ­ation.

It seems I have to wait un­til the prices go down more (and I have some spare money to in­vest without the need for a bank). Re­cently I have read that the ex­pect­a­tion is that in about 3 – 5 years the tech­no­logy to print photo­vol­ta­ic cells can be pro­duc­tion ready, which could re­duce the price to a tenth of what a photo­vol­ta­ic cell costs ATM. In­vest­ing 20 – 30 T€ is not some­thing I would do from one day to an­oth­er, 4 – 5 T€ for a sim­il­ar in­stall­a­tion sounds more easy to agree to.

While I am at it: so far I only see photo­vol­ta­ic info re­gard­ing the peak power a cell can gen­er­ate. To me this does not look in­ter­est­ing. The peak power will be gen­er­ated most of the time in sum­mer (dir­ect sun­light, no clouds, long sun­light times), but in the sum­mer the con­sump­tion of power is less than in winter (less light to use, more time spend out­side the house so less time in front of a TV, more BBQ so less cook­ing in the kit­chen, …). More in­ter­est­ing to me would be a good power gen­er­a­tion in less than op­tim­al situ­ations like in winter when it is cloudy (but it is prob­ably hard to come up with an use­ful value, as the av­er­age for “less than op­tim­al” var­ies from loc­a­tion to loc­a­tion). I have seen a re­port about wa­ter heat­ing (at­tached to the cent­ral heat­ing) with sol­ar en­ergy, where a sys­tem is used which has a lower peak power, but a bet­ter power out­put in less than op­tim­al weath­er con­di­tions (round col­lect­ors where used in­stead of flat pan­els). So the­or­et­ic­ally there is the pos­sib­il­ity to get more power out in not so good con­di­tions, but so far I did not find any in­form­a­tion if it is tech­nic­ally pos­sible ATM to op­tim­ize photo­vol­ta­ic cells to such situ­ations, and if it is if there are some cells avail­able for a sane price.

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