PowerSwitch

[Tarrel]

..Well, in a small way!

I finally got round to ordering the panels for our little DIY grid-tied solar PV system yesterday.

They're going on the shed roof here, which is the sunniest spot in the garden (usually!)



The system will be:
- 5 x 100W panels with a Vmp of 17.5V, connected in series to:
- Mastervolt Soladin 600 grid tie inverter, which is connected into the grid.

Total all-up cost will be around £800 including connectors, etc.

I'm doing this:

- To reduce (albeit by a small amount) use of grid-supplied electricity
- To take another step away from the financial system
- To inflation-proof our energy use
- To get a return on investment on a small amount of capital (I reckon I'll get around a 10% return, which will allow pay-back of the capital over 20 years plus give me 5% "interest" on the money
- To get the money out of the bank
- As an experiment. If it delivers the output I hope, I'll stack another five panels on top of the first five, together with another inverter. i.e. replicate the system.

Ultimately I've probably got room on the shed and on stand-alone frames in sunny spots for four such "modules", giving us a total of 2 kWp.

A separate project is a battery back-up system, charged from the mains, with a normal inverter for resilience in power-outages. As discussed on here in the past, the panels could be easily reconfigured to charge the batteries in the event of a long term grid-down situation. In this case we'd power our priority appliances off the batteries using that cutting-edge piece of technology known as an extension lead and socket-strip.

I imagine we'll use pretty much all we generate, especially with only the initial experimental module, as we have electric cooking and water heating in the summer when the Rayburn is shut down. Power generated is likely to vary a lot through the year. In high summer we have over 18 hours daylight, so this is very much a summer facility for us. During those days, however, we should have some power available during all our waking hours.

Will post updates in due course.
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Engage in geo-engineering. Plant a tree today.

[RenewableCandy]

Oooh well done Tarrel and good luck

Are you getting FiT with that or have you decided it's not worth the hassle?
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Soyez réaliste. Demandez l'impossible.
Stories
The Price of Time

[Tarrel]

[kenneal - lagger]

I hope you've taken the tree down or moved the shed in front of it or does the sun sneak in under the tree branches?
_________________
Action is the antidote to despair - Joan Baez

[RenewableCandy]

Ken, this is somewhere North of Scotland. The sun only ever grazes the surface, it'll come in under that tree like "under the radar".
_________________
Soyez réaliste. Demandez l'impossible.
Stories
The Price of Time

[Tarrel]

Yes, that's right. I watched it all last year and the sun comes in under the branches. There were some offending ones but I've removed them. The trunk doesn't cast a shadow until later in the afternoon.
_________________
Engage in geo-engineering. Plant a tree today.

[RenewableCandy]

Wood Pile Envy, btw
_________________
Soyez réaliste. Demandez l'impossible.
Stories
The Price of Time

[Tarrel]

Not looking its best. It needs topping up from the "master pile" at the woodland. A job for this week, among many others.
_________________
Engage in geo-engineering. Plant a tree today.

[Tarrel]

Panels arrived last week and I fitted them onto the shed roof today.


First two panels in place. Note 4mm cables, terminating in mc4 connectors.


The completed installation. Frame was made from recycled timber, rescued from when we converted the garden studio into my Mother's apartment.


Cables from each panel pass through into the shed below. This gives ready access to the wiring.


Cables from one of the panels, from inside the shed. These will be connected in series (red lead on one panel plugs into black on the next, and so on) to give 60-100V into the grid tie inverter. However, they can be readily unplugged and reconfigured in parallel to feed a 12V battery bank via a charge controller, in the event of a long-term grid-down situation. (said batteries will be kept charged from the mains via a regular smart charger for short-term power-outages).


Result! The output from one panel (reading shows voltage) at about 3.00pm this afternoon.

Now awaiting delivery of the Soladin inverter and an additional length of DC cable. Should be a simple step to connect the panels to the inverter, mount it to the wall and plug in.
_________________
Engage in geo-engineering. Plant a tree today.

[biffvernon]

[Tarrel]

See RC's post above!

[Tarrel]

Been in full sun since 08.00 this morning.

Just realised, I was measuring the open-circuit voltage yesterday!
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Engage in geo-engineering. Plant a tree today.

[Catweazle]

My trees lost many small branches this winter, mostly old dead wood, you wouldn't want it falling on your panels.

[kenneal - lagger]

If you lifted them up by about 40 degrees you would probably get half the output again.
_________________
Action is the antidote to despair - Joan Baez

[Tarrel]

We have never expected to optimise output from this little installation. That's the main reason I have gone down the low-cost, DIY route rather than investing a lot of money, claiming FITs, etc.

There are a couple of issues:

1. The site is not ideal for solar. There are limited areas that are in full sun. The site is largely shaded, and the sun doesn't rise above the local horizon at all for 3 weeks either side of the winter solstice. The site does have other advantages, in that it is very sheltered and avoids the worst of the winter storms.

2. We are a listed building. Technically, the panels need planning consent, as they are within the curtilage of the building (even though they are on an out-building). The application alone would cost a few hundred pounds. So, I'm trying to keep the installation as unobtrusive as possible.

3. We are generally in a very sunny area (in terms of average hours per year). So, the strategy is to make the most of the installation during the summer months and expect very little during the winter (low sun) periods. This favours a lower angle of elevation. (Not quite as low as ours, but see (2) above.)

Some of the above issues also affect any wind potential, and solar thermal. This is why our main priority (both in time and investment) was to switch to a wood fired heating system. The Rayburn we have actually saves us quite a lot of electricity in terms of cooking, kettle, ironing, etc. So, we have solar power "through the back door" so to speak; sun grows the trees, trees are thinned for firewood, firewood provides heat, heat avoids use of elec.

The PV installation is really by way of an experiment. I'll let the proof of the pudding be in the eating. If it gives a reasonable return on the cost, then I'll add another one. At the end of the day, it does also provide the back-up potential I'm looking for as well. If things go downhill, so to speak, I'm sure subtleties like planning rules will become less important, and I can move the panels to a more optimum location.
_________________
Engage in geo-engineering. Plant a tree today.