Wind Turbine Efficiency?

Lemlin

Hi folks,

I've seen a few threads going around on wind turbines but I wanted to try and apply the cost to my own home.

The house is 3,850 square foot and has underfloor heating powered by a heatpump throughout. Electrity consumption from 11 October to today has been 2502 units, 1619 day units and 883 night units.

I'm just wondering what size and cost of wind turbine would I need if I was to get one. I realise wind speed comes into it but all I can confirm is that the turbine would be placed on a hill area where there is very little, if any, cover from trees.

Would it be worth investing in a turbine? I'm only interested in investing in one if it'd literally reduce my ESB bills to nothing.

Carlow52

Based on your criteria, the answer is no.

The last 3 winters have seen peak elec demand in Dec at the same time as a high pressure area from the Azores to Warsaw.

High pressure = no wind => what's the backup plan?.

storage in batteries would be impractical

No6

If you are selling your surplus back to the grid when you are not using it it will not matter if ths wind is blowing or not. What you need to do is calculate your annual energy usage in Kw from your ESB bills, add them all up for as many years as you have get your average usage per year!! Then you need to size your turbine so that it will provide your energy usage or more power per year, you will need wind speed, turbine efficiencies roughness class etc etc!! Micro turbines are very troublesome so be very careful!!.

quentingargan

It is difficult to give an answer to this right now because to some extent, the viability of a turbine depends on the feed in tariff paid for unused units.

This is currently made up of two elements; 9c paid by ESB for electricity they purchase, and a 10c top-up on the first 3000 units exported each year. The 9c element expires at the end of this year, and the 10c element expires at the end of February and until we know what they are being replace with, it is hard to commit to an investment.

This is all quite unlike the UK system where you are paid for what you produce, regardless of whether you use it or not, and then get a top up for what you export.

Under the current regime, you want to size your turbine so that as much of your exported power as possible is at the 19c rate, and you don't go too far above 3000 units exported.

You will always be either importing or exporting. Although you have a heat pump, in practice, it cuts in and out, drawing quite a large load while it is kicked in - probably more than most generators would be kicking out at that moment in time.

I don't think you can put in a turbine with financial return on investment being the sole criteria. In my experience, most people who have turbines do so because they like the idea of having clean electricity. Those who did it purely for financial return are, by and large, going to be disappointed at the current feed in tariff, (and I say that as someone working in the industry who has an invested interest in saying the opposite...).

If you like 'em, get one, but don't spend more than you can afford. No6 is right in some respects - there have been failures, including a high profile one in the UK where a long-standing manufacturer went down the tubes telling owners of their €60K turbines to shut them down until further notice...

Lemlin

No6 wrote: »

If you are selling your surplus back to the grid when you are not using it it will not matter if ths wind is blowing or not. What you need to do is calculate your annual energy usage in Kw from your ESB bills, add them all up for as many years as you have get your average usage per year!! Then you need to size your turbine so that it will provide your energy usage or more power per year, you will need wind speed, turbine efficiencies roughness class etc etc!! Micro turbines are very troublesome so be very careful!!.

The ESB was only installed in the house in July and we only moved into the house in September so its impossible to tell what my yearly spend will be yet.

I don't want to make a profit from it, what I want is a turbine which could cover my own electricity cost 100%.

Coles

Some rough 'back of the beermat' calculations....

Your annual electricity usage will probably be about 10000 kWhrs (units) at a cost of €2000. If we assume you want to meet all your electricity costs from a micro turbine and you use about 5000 units of your own production (off setting a cost of €1000), you will need to export a further 11000 units at the paltry 9c/unit to fully cover the rest of your electricity bill.

So 16000 units per annum need to be produced, and the load factor of a well sited micro turbine might be 15%, so the capacity of the turbine would need to be (16000/15%/(24x365)) 12kW. (The load factor could be a lot less depending on the site and the turbine. You should ask the installer to guarantee it, just for fun.)

How much will a 12kW wind turbine cost installed? I have no idea, but it would be hard to justify it if it can't give a simple 8% return on investment (extra return to allow for maintenance costs), so if it costs more than €25k it probably doesn't make sense. However, this investment would protect your energy bills from inflation, and you could make a greater return on investment by finding ways to use the energy productively yourself (electric vehicles), so it might make sense even at a 6% return on investment, or €32k.

refco

i think because either is expensive if you where seriously looking you should consider solar pv panels expensive but efficient but no planning needed im told i know of a house in west cork who have them and where amazed because they did double the output the company selling them claimed they would do over the first 12 months dont have any proper details but could get a contact for you if interested