Solar panels and feedback to the grid, or not?

Do you have a query on how to get things done in Andalucia, where to find things, who to call? Find out by posting and hear about others experiences.
Lavanda
Andalucia Guru
Posts: 4214
Joined: Thu Jul 29, 2004 1:42 pm
Location: Cáceres Province, Extremadura

Re: Solar panels and feedback to the grid, or not?

Postby Lavanda » Fri Jul 06, 2018 12:56 pm

I’m not too keen on storage in batteries. They are expensive, don’t live very long (10years?), and are inherently a bit dangerous, as they contain a lot of energy.


I wouldn't go with Tesla batteries yet, they are still quite expensive and we don't know how many years they last. If you buy Tesla you lock yourself into their system and you probably have to use their charge controller and so forth. It is likely you need a different capacity than they offer aswell.


We are not on any grid so just use solar power. We pay no taxes or anything like that. We just power our home with solar power and mind our own business.

However, we have just had a state-of-the-art lithium battery system installed (not Tesla but some German thing). Nine panels, one battery, 20 year guarantee, no maintenance. We can now power everything we want and need. It's a HUGE step up from the old lead-acid batteries and the installation was just about the same cost as the system we had installed ten years ago. If you wait another year or so it will be even cheaper.

User avatar
rickj
Tourist
Posts: 22
Joined: Mon Apr 20, 2015 7:05 pm
Location: Antas, Almería

Re: Solar panels and feedback to the grid, or not?

Postby rickj » Fri Jul 06, 2018 5:53 pm

Sounds expensive. Can you tell us what your system cost, roughly?

Lavanda
Andalucia Guru
Posts: 4214
Joined: Thu Jul 29, 2004 1:42 pm
Location: Cáceres Province, Extremadura

Re: Solar panels and feedback to the grid, or not?

Postby Lavanda » Fri Jul 06, 2018 7:21 pm

Just under €11,000 for everything including delivery, all the work in setting it up, testing, etc, everything. So, with a 20 year life-span that's not cheap but not bad, either. However, we have no option as we are KILOMETRES from any mains electricity and the lead-acid batteries were coming to an end after 10 years but we didn't want to re-invest in the old technology. That was a no brainer.

User avatar
rickj
Tourist
Posts: 22
Joined: Mon Apr 20, 2015 7:05 pm
Location: Antas, Almería

Re: Solar panels and feedback to the grid, or not?

Postby rickj » Sat Jul 07, 2018 6:58 am

We pay about €100 per month. No airco. So 1200€ a year, roughly your system costs 10 years of my electricity bills.
Panels last 25 years+, but I wonder if battery and inverter will last your 20 years. How long is the warranty period on the battery?

Personally I think I’d rather not have a battery but more panels, and do the energy intensive things around noon. My energy consumption after dark is quite low, a few hundred watts max. TV, computer, fridge, some led lights. We’d use the grid for that.

Lavanda
Andalucia Guru
Posts: 4214
Joined: Thu Jul 29, 2004 1:42 pm
Location: Cáceres Province, Extremadura

Re: Solar panels and feedback to the grid, or not?

Postby Lavanda » Sat Jul 07, 2018 7:44 am

The warranty is 20 years, as I wrote. It seems incredible but that's what the paperwork says.

championc
Andalucia.com Amigo
Posts: 34
Joined: Thu Nov 10, 2016 7:50 pm
Location: Mojacar / Dublin

Re: Solar panels and feedback to the grid, or not?

Postby championc » Sun Jul 08, 2018 5:58 pm

Thanks @rickj for the advise regarding the Micro-Inverters and the single panel. I absolutely know it's uneconomic right now but I reckon it's worth chucking 500 or so at a "pilot"project of discovery !!!

TorreDelAguila
Resident
Posts: 1140
Joined: Thu Jan 23, 2014 11:52 am
Location: Sayalonga

Re: Solar panels and feedback to the grid, or not?

Postby TorreDelAguila » Sun Jul 08, 2018 7:18 pm

I think Endesa are pretty much solely interested in selling as much expensive electricity as they can, and while they are more than happy to invest in Solar themselves, they really don't want others - especially their customers - to do the same, even at a domestic level. Possible that the change of government might kick them in the right direction.
Chris

User avatar
rickj
Tourist
Posts: 22
Joined: Mon Apr 20, 2015 7:05 pm
Location: Antas, Almería

Re: Solar panels and feedback to the grid, or not?

Postby rickj » Sun Jul 08, 2018 8:33 pm

There is a partnership between LG and Enphase where a solar panel has an Enphase micro-inverter attached already. I think it will supply 230v without extras: Neon 2 Ace https://www.lg.com/us/business/solar-pa ... g-neon2ace
Don’t know if it’s available in Europe.

championc
Andalucia.com Amigo
Posts: 34
Joined: Thu Nov 10, 2016 7:50 pm
Location: Mojacar / Dublin

Re: Solar panels and feedback to the grid, or not?

Postby championc » Mon Jul 09, 2018 5:02 pm

rickj wrote:Personally I think I’d rather not have a battery but more panels, and do the energy intensive things around noon. My energy consumption after dark is quite low, a few hundred watts max. TV, computer, fridge, some led lights. We’d use the grid for that.


Interesting - so am I correct to say that you have no battery at all and that the panels connect directly to the micro-inverter and therefore, It's a case of "use it or lose it" power, waiting for possibly lithium batteries to come down in price ?

And is there much of an issue to OverSize the panels vs the consumption ? I'm sure you don't want a 1kW array when most of the time you'd only be using .5kW

User avatar
rickj
Tourist
Posts: 22
Joined: Mon Apr 20, 2015 7:05 pm
Location: Antas, Almería

Re: Solar panels and feedback to the grid, or not?

Postby rickj » Mon Jul 09, 2018 8:19 pm

Or, use it or don’t generate it. With micro-inverters you can switch off the ones you don’t need at the time. I assume that is how a zero-grid-feed is implemented by Enphase when you use that type of profile. There are more places where you cannot feed energy into the grid, like Hawaii.

I don’t mind installing a 1kW array while not using all power always. In fact I think I’ll install a 3 kW array (ca 10 panels), in steps, and see how I fare. We have an electric boiler for hot water, an oven,a washing machine and a dishwasher etc, that we’d use at peak sun.

championc
Andalucia.com Amigo
Posts: 34
Joined: Thu Nov 10, 2016 7:50 pm
Location: Mojacar / Dublin

Re: Solar panels and feedback to the grid, or not?

Postby championc » Wed Jul 11, 2018 9:03 am

For water, consider my setup
viewtopic.php?f=1&t=32520&p=361627#p361627

User avatar
rickj
Tourist
Posts: 22
Joined: Mon Apr 20, 2015 7:05 pm
Location: Antas, Almería

Re: Solar panels and feedback to the grid, or not?

Postby rickj » Wed Jul 11, 2018 9:29 am

We did! And in the end decided to go for a simple 80 liter class B water heater.

We are two, and don’t use much hot water at all, just for a shower. We had a gas boiler (geyser) with a gas bottle, which was not nice for various reasons. Worst of all: the pilot flame would empty a bottle in 3 months. We considered a setup like yours, but it costs between 1500-2300€, and we don’t have a very good spot for it either. The roof is an antique Spanish roof, beams, cane, mud and tiles, can’t put a panel on top of that. The location that seems best is 7 meters away from the shower, which is not good.

I even prepared a setup with a reservoir inside the house and just the hot water panel outside, leaning against a wall: the house has a new render, and we put 3 copper pipes in there, both to the garage below and to the room next to the bathroom, so we can have a panel outside, and a choice for the location of the tank.

But in the end we decided to buy an electric 80 l boiler for €180 and not go for the panel+tank setup.

We will have solar pv panels, and possibly quite many, like 10 or 12. The boiler is 1400 W, the peak power of ca 5 panels. Feeding a boiler with pv panels is not the greatest combination, I know, but you can’t have everything.

I’m still tempted to hook up a hot water panel to the current setup, using the tubes in the wall, and preheat the electric boiler’s contents with that. Maybe later. Other projects have higher priority now :-)

championc
Andalucia.com Amigo
Posts: 34
Joined: Thu Nov 10, 2016 7:50 pm
Location: Mojacar / Dublin

Re: Solar panels and feedback to the grid, or not?

Postby championc » Thu Jul 12, 2018 12:03 am

And just to confirm with your setup, does the PV panels connect directly to the micro-inverter or is anything else needed in between ?

User avatar
rickj
Tourist
Posts: 22
Joined: Mon Apr 20, 2015 7:05 pm
Location: Antas, Almería

Re: Solar panels and feedback to the grid, or not?

Postby rickj » Thu Jul 12, 2018 6:29 am

The micro-inverters are mounted directly on the back of the panels. The inverters then generate 230V directly. Note I don’t have a system yet, I’m awaiting availability of the new IQ7 inverter, that should be available about now.

championc
Andalucia.com Amigo
Posts: 34
Joined: Thu Nov 10, 2016 7:50 pm
Location: Mojacar / Dublin

Re: Solar panels and feedback to the grid, or not?

Postby championc » Thu Aug 16, 2018 11:10 am

Bad news for now it seems. I contacted Enphase who said I'd need an IQ Envoy to block the feedback. I then contacted Segen.co.uk the distributor who said

When Enphase were originally doing their IQ training they touted the IQ7 microinverter as having AGF (Advanced grid functionality), features which would include being able to create its own grid reference signature and essentially work off the grid and also when installed with an Envoy they would be able to limit their export back to the grid.

Currently the system isn’t G100 approved and these features have not been released nor are available in the UK as of yet.

So long story short, the IQ7’s can’t achieve EPM with or without an Envoy at the moment.

User avatar
rickj
Tourist
Posts: 22
Joined: Mon Apr 20, 2015 7:05 pm
Location: Antas, Almería

Re: Solar panels and feedback to the grid, or not?

Postby rickj » Thu Aug 16, 2018 12:04 pm

Thanks for that info! I’ll see what the scope of the G100 requirements are.

As I understand it, for zero feedback you do need an Envoy, but the metered version. That has two current transformers that it uses to measure how much power is drawn from the grid, and how much power is generated by the inverters. By applying a zero-feedback “profile”, which I understand to be the configuration of the Envoy, it will make sure no power is fed into the grid. It should work by changing the amount of power generated by the individual inverters, or by simply switching them off.

Enphase uses that in places like Hawaii. But, it is only possible with later models inverter, S- series, and iq. So far S- series has not been available in Europe, just in Australia. IQ is now “expected” in September.

I’ll be extremely irritated if zero feed grid still is not possible with iq7, as I’ve waited a year for that.

If all fails I’ll simply buy a bunch of M250, possibly cheap, and do a zero feed grid myself. I can program Arduino, and know about electronics. I’ll give every inverter it’s own relay to switch it on or off, and do the power measuring myself. That way making sure to never produce more power than is used, and switch the production on/off by 300W, the power generated p by one inverter.

As far as I know iq7 was never intended as stand alone grid. That should come with the next inverter, iq8.

All in all, I’ve done quite some messaging with Enphase, as some people said zero feedback is possible with M250 too. Only because I’m not that trusting and stubborn I found it it is NOT possible. But never heard that directly from Enphase.

Be wary!

Those panels with integrated inverter from LG should work standalone, without Envoy, as long as you are allowed to feed the grid. Zero feedback really is a hassle!

Best,

Rick
Last edited by rickj on Sat Aug 18, 2018 10:38 am, edited 1 time in total.

User avatar
rickj
Tourist
Posts: 22
Joined: Mon Apr 20, 2015 7:05 pm
Location: Antas, Almería

Re: Solar panels and feedback to the grid, or not?

Postby rickj » Sat Aug 18, 2018 10:38 am

Here is a description on how Enphase microinverters limit production to achieve zero-feedback to the grid:

https://enphase.com/sites/default/files/downloads/support/TechBrief-Export-Limiting-HEI-Self-Supply-EN-US.pdf
(pdf)

"An Enphase system can support Customer Self Supply by using a special CSS profile and an IQ Envoy with consumption CTs installed at/near the utility service location. When configured for CSS, the Enphase system still automatically limits the PV generation so that no energy is exported to grid."

"The Enphase Energy Management System uses data collected by the or IQ Envoy consumption and production meters and automatically adjusts the output of the microinverters anytime that the output of the PV system is capable of exceeding the sites consumption needs. This power curtailment functionality is essential to maximize the system output while limiting the export of power to the grid. These adjustments to microinverter power output are sent from the Envoy over the powerline, meaning there is no need for external communications to be installed. Pulling data from the consumption meter every 500ms and making adjustments to microinverter output at 1.5 second intervals, an IQ Envoy with self-consumption enabled will consistently react to inadvertent export events in two to four seconds, well within the 30 seconds allotted by the utility."

I think my description above matches this more or less :-)


Return to “Living in Andalucia”

Who is online

Users browsing this forum: No registered users and 11 guests