Now we have a swimming pool with a 1.2kW pump, running 8-9 hours a day, the decision to install solar panels has become more urgent. A big consumer like this costs 2€ a day, or about 800€ a year, while the sun is shining constantly. Alas, a private solar installation is not as easy a purchase as in The Netherlands. In the Netherlands you can feed back your surplus electricity to the grid, and you get paid for that too. In Spain the government decided to tax power generated by private solar panels. The lobby is strong, apparently. The idea is that you buy less electricity from the electricity companies, and thus you disadvantage other consumers. Of course it's just an obnoxious law, that "Europe" is protesting. But, the government here has been out of a majority for a very long time, and nothing much happened, and the law has not yet been changed.
What to do. We don't want to go "off the grid", and become totally independent. By day you use power form the panels and you charge the batteries. At night you use the stored power. But batteries are expensive, dangerous, end short lived (ten years). Remains "grid tied", where you use your own power first, and if your panels don't yield enough you use power from the grid.In the Netherlands that is all arranged, but here in Spain it isn't. There is another option: you do connect your solar panels system to the grid, but you don't feed back surplus power to the grid. That is called "zero grid feedback", or "self consumer". Zero feedback would be nice. No fuss with taxes, you are sort of independent, but you can still use power from the grid, if needed, like at night.
What/which system, and how big? Well, preferably more than 1.2kW for the swimming pool pump. But, do we keep on cooking with gas (bottles), or do we switch to electric? Atag refuses to market its products in Spain, see http://jansenendewaal.blogspot.com/2017/03/oven.html, so we could switch to electric cooking. A big electric "burner" is ca. 3kW, though that is not all day. And are we going for an electric car? As you can see we'd like to start small, ca. 1.5 - 2kW, and extend later.
But, the "inverters", the apparatuses that convert the direct current from the panels to 230V/50Hz alternating current are not that flexible. Most like a configuration within their capacity. Capacities range, for example, from 1700 W to 2140 W, while the next bigger version is 2500 to 3600 Watt. These inverters, that convert power from a series of solar panels, are called "string inverters".
There is another option: a mini-inverter, where each solar panel has it's own small inverter. Buy an extra panel, buy another mini-inverter. The manufacturer of these inverters is called Enphase: Enphase (https://enphase.com/). Good! Hm, no dealer in Spain. Yes in The Netherlands, France, Germany. Understandable, if Spain is making life for solar people difficult. But you can order your supplies by internet, and diy the installation, which is easy with Enphase.
Another advantage of micro-inverters is that they are long lived, about 25 years, versus 10 years for string inverters. And, a system built with separate inverters is very good with shaded panels. It will simply shut off panels that are shaded, and not the entire system.
Remains the choice for grid-tied, and yes or no zero-feedback. Before you know if this is possible with Enphase a lot of water has not run through the Rio Antas. Enphase themselves don't tell you much about zero feedback on their website. "Contact us" gives me no response (twice). My internet dealer says "I think it's possible". Ask on a forum, and one person says "yes it is possible", the other says "no you can't". Let's study this topic ourselves then.
Enphase has a number of series inverters that are basically compatible:
Modern solar panels yield 280-300W at the sunniest moment of the day.
Enphase does say something about zero-feedback: you need to apply a "zero feedback grid profile" using your Envoy. The Envoy is a small box that controls and monitors your collection of inverters, and delivers nice statistics and graphs via wifi. On Hawaii there are regions where you need to apply this zero feedback grid profile. But, you need a more recent series of inverter than is available in Europe: the S-series or the IQ. In Europe only the older M-series is available.
Strange people at Enphase.
And still no answer from Support.
Ticket : 00982541
Submitted : 6/24/2017
Subject : Solar panels system with Zero feedback to grid - Envoy-S standard or metered?
After some more studying you encounter a comparable manufacturer: SolarEdge, who also have sort of a micro inverter, and a scalable system. It's the same company IKEA uses for their solar panels systems. But, SolarEdge is from a country I prefer not to do business with. Yes, Israël.
Studying further you see the financial situation of Enphase is not that great. Not strange if your support department does not answer and you don't market your products in Europe.. Anyway, 25 years lifespan and guarantee does require a company that is still around after 25 years.
Next year (2018) they will market the 7th generation "international inverter" that will make everybody happy.
But what am I to do now? I would be perfectly happy with the M250 inverters, but then I need to be able to install a system here in Spain that is allowed to feedback the grid. No answer about that from ENDESA, who are not overflowing with information either. Their support department is the same as Enphase's, apparently: still no answers.
Sigh.
No comments:
Post a Comment