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Treacodactyl

Solar generator / UPS / backup thingamy

We've been considering a couple of UPS devices for various reasons. What's put me off is the cost for good quality ones and their limitations. I've also been considering some form of solar set-up, at least what needs to be done to a house in preparation for the addition of one.

Today we bumped into someone selling a system that makes use of a grid tied solar array and stores some of the power in a battery for later use. The aim is to use more of your power but I noted it'll also perform a whole-house UPS function and would reduce/remove the need for a fossil fueled back-up generator. As you're grid tied the batteries can be topped up in the middle of winter from the grid so they'll be ready if you get a long power cut.

Anyway, here's the system they were selling: http://www.victronenergy.com/inverters-chargers/ecomulti . It's not cheap (especially once batts are factored in) but has anyone heard of such systems? Any recommendations or alternatives?

What I'm interested at the moment is seeing what options are out there and what I might need to do if I renovated a house. For example, it was suggested to have two consumer units - one for grid only and one for your grid-tied solar set-up.
vegplot

It looks interesting although I would expect it to have an auto grid disconnect wired to allow the use of a single consumer unit. I've not looked at the information data sheet so it may well have.
Hairyloon

You have to have an auto disconnect from the grid, else if there is a power cut, then you are still keeping your section live. Bad news for the engineer who wants to fix it.
Treacodactyl

It looks interesting although I would expect it to have an auto grid disconnect wired to allow the use of a single consumer unit. I've not looked at the information data sheet so it may well have.


It does have a disconnect I believe, the dual consumer unit would be more for my benefit. I.e. wire up equipment we need to one linked to the Ecomulti (freezer, lights, PC) and other equipment to the other (washing machine etc).

Now that may well not be necessary but worth thinking about.
vegplot

This might be of interest in our new build.
Treacodactyl

Interesting, if it makes it over here. http://www.teslamotors.com/powerwall


Quote:
Technology
Wall mounted, rechargeable lithium ion battery with liquid thermal control.
Models
10 kWh $3,500 For backup applications 7 kWh $3,000 For daily cycle applications
Warranty
Ten year warranty with an optional ten year extension.
Efficiency
92% round-trip DC efficiency
Power
2.0 kW continuous, 3.3 kW peak
Voltage
350 – 450 volts
Current
5 amp nominal, 8.5 amp peak output
RichardW

Interesting, if it makes it over here. http://www.teslamotors.com/powerwall


Quote:
Technology
Wall mounted, rechargeable lithium ion battery with liquid thermal control.
Models
10 kWh $3,500 For backup applications 7 kWh $3,000 For daily cycle applications
Warranty
Ten year warranty with an optional ten year extension.
Efficiency
92% round-trip DC efficiency
Power
2.0 kW continuous, 3.3 kW peak
Voltage
350 – 450 volts
Current
5 amp nominal, 8.5 amp peak output


So at best thats 11p per kWh if you use all 7kWh per day every day for 10 years with no other costs due to servicing or repairs.

I dont think I want to buy my next 10 years worth of elec in one go.
Nick

It's new technology. It's going to be expensive, and designed for industry and early adopters. Relax. You're not a target audience. Smile Treacodactyl

I dont think I want to buy my next 10 years worth of elec in one go.

The numbers don't seem to make sense just to use cheap night time leccy, no. However, I was thinking it would be more useful in areas where the power isn't that reliable.
Treacodactyl

It's new technology. It's going to be expensive, and designed for industry and early adopters. Relax. You're not a target audience. Smile

I'm not sure about that. The basic idea has been available for a few years now and looking at the details from Tesla they're building a new factory ready for 2020, so I can't see this is going to be that viable for a few more years.
Nick

That's how technologies emerge. RichardW

If you want to use all your locally made elec on site then get an Emma or similar & turn it into hot water.

Unreliable power is a different matter.

Just how unreliable?

A small cheap petrol genny might be a better solution.
Treacodactyl

That's how technologies emerge.

Some faster than others. The basic idea and some products has been around for so long I would expect a better offering. I note in some of the reports they question whether a better technology will come to market before the Tesla batteries get established.
Treacodactyl

If you want to use all your locally made elec on site then get an Emma or similar & turn it into hot water.

Unreliable power is a different matter.

Just how unreliable?

A small cheap petrol genny might be a better solution.

Yes, I'm currently looking at the Honda 20i.

We get lots of small power cuts, sometimes only for a few seconds but often for an hour. However, if we move somewhere more remote I expect we could have to put up with over 8 hours without power and possibly longer. That would be rare but when working from home and keeping a couple of full freezers we need something to provide power.

I did look at a smaller battery powered gennie but the run time was just too short.
Nick

That's how technologies emerge.

Some faster than others. The basic idea and some products has been around for so long I would expect a better offering. I note in some of the reports they question whether a better technology will come to market before the Tesla batteries get established.

Oh, very possibly. To get where we want to get, there will be blind alleys and competing solutions.
RichardW



Yes, I'm currently looking at the Honda 20i.

We get lots of small power cuts, sometimes only for a few seconds but often for an hour. However, if we move somewhere more remote I expect we could have to put up with over 8 hours without power and possibly longer. That would be rare but when working from home and keeping a couple of full freezers we need something to provide power.

I did look at a smaller battery powered gennie but the run time was just too short.

Hondas are good if expensive.

Small power cuts are not worth spending money on.

Even an hour is not an issue just have a cuppa (you do have an alternative brewing system?) & enjoy the break.

8 hours for a freezer should not affect it. If it does then it is either not cold enough to start with or the insulation has broken down. New freezers even come with a power cut rating (well our last one did) I think ours is 48 hours.
Treacodactyl

Small power cuts are not worth spending money on.

Not on a gennnie but we may need to do something UPS wise as we've had instances where the power flicks and off from anything from a few seconds to several minutes over the course of an evening.
RichardW

Is that really a problem?

You do know that using a UPS costs lots (relative to the amount of time in use) when they are not even doing anything?

How much equipment (more importantly what do they consume) do you want to keep live during those short outages?
Graham Hyde

Treacodactyl wrote: Not on a gennnie but we may need to do something UPS wise as we've had instances where the power flicks and off from anything from a few seconds to several minutes over the course of an evening.

If you are concerned about TV's and laptops it may be best feeding these through a battery set up. Most flat screen TV's run on a low voltage (12volts) and laptops can also be battery fed.
A small low cost battery and charger could do the job. Don't put back up to 220volts, feed the equipment with 12 volts.
Nick

For under £100 you can run a bunch of things thru a ups with power clean up, so that it copes with spikes, dirty power and outages for an hour or two.

We use them at work to protect equipment and samples routinely.

How much they cost to run and the value they bring will be situation specific.
Treacodactyl

Is that really a problem?

You do know that using a UPS costs lots (relative to the amount of time in use) when they are not even doing anything?

How much equipment (more importantly what do they consume) do you want to keep live during those short outages?

Interesting question, I've been assured that the power cut isn't the issue it's what the rest of the house does during the power cut, e.g. energy saving bulbs dumping power into the house electrics. I've been assured a surge protector, which we've used for years anyway, is all we need to protect equipment.

The next issue is working. That'll depend on the frequency of the outages, perhaps not a problem at the moment but I get the impression things are expected to get worse.

As it's for work costs wouldn't be an issue.

As for an UPS, we'd need a pure sine wave one and they're about £200. Run time isn't great so we'd be looking for at spending £300 - £400. Then, as you say, there's there's the running costs and some people moan about noise.
RichardW

UPS's are not for keeping work going but to allow you to save work & shut down safely.

If keeping a computer working is the issue just change to using laptops. They have a built in UPS lol.


Why are things going to get worse grid wise?
Treacodactyl

UPSs don't just have a single use. If I'm going to spend a fair bit on one to simply cope with shutting down it may well be worth spending a bit more to be able to work during short outages.

I've been looking at laptops (which is a task in itself as I don't want all the latest bells and whistles but a simple, well built, reliable laptop and there doesn't seem many about). However, you still need power for the router to enable you to work.

As for the grid, with less being spent on maintenance, more storms expected etc, etc there will be more power cuts.
Hairyloon

UPS's are not for keeping work going but to allow you to save work & shut down safely.
Or to give you time to fire up the backup generators.

I'm told the UPS system at Yahoo is quite impressive.
Nick

Some systems can't be shut down quickly, and might need an hour to do so.
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