Energy prices-here we go again

Well, my fixed deal with Scottish Power is coming to an end, and the price hikes I described last year seem still to be with us, with the increase on the total bill at 18%, a 15% hike on daytime electricity, a 16% hike on night electricity, and a 19.7% hike on gas.

And then they’ve also cut the discounts offered, and hiked the price on the first units.

So, this is fixed until August 2014.  They do have a cheaper tariff, but there’s an exit penalty.  This special offer has to be chosen by the end of June, and may be withdrawn at any time.

So, my reasoning is that it’s best to lock into this price, and then see if any cheaper deals appear as we approach the winter, as we don’t actually use much energy during the summer anyway.  Fingers crossed for some price drops.

 

Electricity prices Your current prices* Your new prices1 from 1st July 2013* Your alternative Offer prices2 from 1st July 2013* Online Fixed Price Energy July 2013 Offer Standard monthly Direct Debit Online Fixed Price August 2014 Offer Daily Service Charge   27.39p   First 225kWh used each quarter 20.785p   23.906p All/Day remaining kWh 10.926p   13.436p All/Day Units kWh   14.256p   Night Units per kWh 5.448p 6.742p 6.354p

Gas prices	Your current prices*	Your new prices1 from 1st July 2013*	Your alternative Offer prices2 from 1st July 2013*
	Online Fixed Price Energy July 2013 Offer	Standard monthly Direct Debit	Online Fixed Price Energy August 2014 Offer
Daily Service Charge		27.39p
First 670kWh used each quarter	7.099p		7.294p
All/Day remaining kWh	3.156p		3.778p
All/Day Units kWh		4.009p

Solar PV a year on and some illuminating thoughts

At the beginning of September, our 2100 kWp Solar PV array had been installed for an entire year.  The output was 15% over what had been predicted by the installer, generating  just under 2000 kWh in the year, and the investment is still looking to pay off in just over 7 years.

I also noticed that for the price I paid, you can now get a system that’s twice as big, so even though the FIT rate has halved, you can still get your investment back in 7 years, while generating twice as much as I am.

However, in the Northern Hemisphere, the days are getting shorter (watch it change on your PC’s desktop with Terminator for Windows Desktop) and it’s got me thinking about how we can shave bit more off of our consumption.

Ikea have an offer on in the UK for the next few days, giving you £3 off each LED bulb you buy.  This website also looks promising: http://www.directleduk.co.uk/

Should I replace all my CFL bulbs?

For example, this 60W replacement (at £11.95) replacing an 11W CFL bulb to a 5W bulb will pay for itself after 100 kWh at 11p/kWh, or about 20000 hours.  Assuming the light is on for an average of 3 hours a day, that will take 18 years to pay for itself—maybe not worth it just yet, as you can currently get CFL bulbs for about 10p each in the UK (heavily subsidised).

What about CFL downlighters?

We do however also have 8 CFL downlights that are probably reaching the end of their life (they’re on many hours a day in the kitchen), and the best price I can find at the moment for them is Pack of 3 - Megaman BR0711i Ingenium GU10 Spot Bulb 11W Warm Whitefor £14.99.  Where these apparently direct replacement GU10 LED 4.5 W  lamps are £9.95.  If the lights are on 4 hours a day, I save 10p every five days, saving £7.30 per year.  Replacing all 8 bulbs (£40 difference in price) will take just over 5 years to repay the investment, so this probably is worth doing.

How about Fluorescent Tubes?

We also have some fluorescent tubes in our bathroom placed beside a large mirror.  Three of these at 30W uses quite a lot of electricity, and I actually don’t like them very much anyway.  Also, the seem to light up a lot of the box they’re in and not so much of the mirror.  But, these IP68 LED Tape Lamps look like they might be exactly what I need.  5 meters of tape should be enough for the job at 24W and output 1800 Lumens, and again will cost just under £40, and I’ll also need a driver for the LEDs that costs about £20.  Every 15 hours these are on, I’ll save 1Kw of electricity, so they’re paid for in 9000 hours, which at an hour a day for a bathroom will take around 24 years to pay back.

That’s not a great return, but I might do it anyway.  I can probably build it in such a way that if they don’t work there, I can repurpose the strip of lights for use somewhere else.

More energy price hikes

I just got notice that my current tariff for electricity is set to end.

Lo and behold!  Prices are now going to go up 12% for electricity, and 6% for gas for me if I switch to their cheapest deal.

Or I can opt for a fix until July 1, 2013, at about the same levels as I’m currently paying.

Does anyone think prices might actually drop over the winter period before then, as that’s the period where we use the bulk of the electricity?  If so, let me know.  At this moment, I’m tempted to go for the fixed rate based on the cynical winter price rises we’ve seen for the past few years.

By the way, for anyone interested in the existing rates from Scottish power.

Your energy details at a glance
Electricity prices	Your current prices	Your new prices from 1st May 20121	Your alternative Offer2
	Online Energy Saver 13*	Standard monthly Direct Debit*	Online Energy Saver 18*
First 225kWh used each quarter	21.006p	22.267p	20.975p
All/Day remaining kWh	9.777p	11.706p	11.027p
Night Units per kWh	5.174p	5.837p	5.498p
Gas prices	Your current prices	Your new prices from 1st May 20121	Your alternative Offer2
	Online Energy Saver 13*	Standard monthly Direct Debit*	Online Energy Saver 18*
First 670kWh used each quarter	6.730p	7.606p	7.164p
All/Day remaining kWh	2.992p	3.382p	3.185p

Energy consumption down, but efficiency is too

It’s been a warmer than average winter, only 75% as cold as last year according to an independent source, and my calculations bear that out too.

Season	Degree Days @17.5C	Average Per Day
2008-2009	2134	10.51
2009-2010	2121	10.45
2010-2011	2072	10.21
2011-2012	1567	7.71

This smaller temperature difference  complicates things, as we now have a much bigger effect from our baseline usage, which had been ignored in previous calculations.

	Low Rate Electricity	High Rate Electricity	Gas	Average Total	Per Degree Day
08-09	7.20	16.30	71.90	95.40	9.08
09-10	7.09	16.18	62.52	85.79	8.21
10-11	7.14	18.46	60.73	86.33	8.46
11-12	5.49	15.38	50.42	71.29	9.24

As you can see, our total energy use per degree day has actually increased, despite the changes made with better lighting and timed radiator valves.  In addition, we reduced the heating to only 7.5 degrees in a 3m x 4m room at the back of the house with 3 outside walls which uses electrical heating.  I have to admit, I’m disappointed.

Maybe if we look at the numbers differently.  Our baseline gas usage appears to be about 12 kWh/ day, and our electricity usage about 8 kWh for high rate, and 4 kWh for low rate.

Below is the table with units of kWh per degree day.

	Low Rate Electricity	High Rate Electricity	Gas	Total
10-11	0.307	1.024	4.772	6.104
11-12	0.193	0.958	4.983	6.134

While this is better, you can see that the overall usage is still the same, with no measurable effect from the changes, though High Rate electricity is actually down 7 per cent, and low rate is down 38 per cent, but gas usage is actually up 4 per cent, overall though we used 0.5% more energy per degree day than last year.

I’ll have to put this down the the fact that we have the gas fire on in the lounge in the evenings, and it is really toasty in there.

The other good news though is that we did manage to generate .45 kWh of high rate electricity per degree day over the period, which is included in the consumption figures above.

So in terms of fossil fuels, our consumption has dropped by 7% over the period.

In terms of absolute cost, we used 18%  less energy we did in the previous heating season, but that was unfortunately offset by an 18% rise in prices over the same period, so costs were similar to the previous year.

LED Lighting photos

Yesterday, my sister complained there weren’t any pictures.  Well, here they are:

First, the light fixture the LED’s were replaced into in the bathroom.  The one on the right is the LED, as is the one you can’t see on the left.  I had to leave one halogen, so left it in the middle pointing to the mirror.  This fixture used to be 60W, it’s now 26, and the light appears to be the same warm color from both the LEDs and the halogen.  Output is 285 Lumens, but they are not dimmable.

The photo on the right is of the lamp directly above the mirror.

This is a 240V 50W halogen equivalent led drawing 6W with a GU10 fitting.  Again, the light is a very warm color.  You can see in the reflection on the tiles, the 3 individual LEDs.

This was done before, and isn’t counted in the costs below.

 

Finally, the rebuilt desk lamp that had failed.  The old plastic head is on the desk for comparison, with its 20W capsule halogen, compared to the new 3W LED.

You can see that the clamps cause the arms to splay out slightly, but it doesn’t appear to be putting any excessive strain on the fitting.

The lamp is quite a bit larger than the one that was originally in this fitting, but I don’t think it looks too bad from the angle I see it from most of the time.

The total cost of this project was £17.94, and given I replaced a desk lamp that was broken, I think was very good value.  And £10 of the total was an Amazon gift voucher for using their credit card!

Payback time on the project on energy costs alone looks like this:

Old wattage: 60+20 = 80 W
New wattage: 3 + 20 + 3 + 3 = 29 W
Difference = 51 W

Cost savings per hour at 51W = £0.0055

so £17.94 / £0.0055 per hour = 3261 hours

At two hours a day that’s 5 years, and a CO2 saving of 1400 kg to boot.  Lifetime of the lamps is forecast to be 50000 hours, so I should never have to replace them.  We’ll see how they cope in the moist environment of the shower room.

More LED Lamps

Yesterday, I ordered some new 3W LED 12V bulbs to replace the 3 20W lamps currently in the kids bathroom.  I had been warned that I might need a new transformer, and that they might not work without changing it.

My brother-in-law is an electrician in France, and I asked him about the likelihood that they wouldn’t work, and he thought it would probably be worth a shot, but he had said that electronic transformers might not like such a low current draw.

Well, I plugged all three in, and it appeared to work, however after a short time, I noticed a distinctive hum.

The solution of course is to plug in one of the original 20W halogens, taking the load of the light from 60W to 26W with the new bulbs.  Still a big improvement!

As for the third bulb, I happened to have a failure simultaneously of my halogen desk lamp, which has a transformer, and two antennae which carry the 12V AC.  And from our redecoration of the kitchen several years back, I had kept an old halogen light fitting that clamped onto two rails.

So, a quick unscrew of the old fitting, and a clamp on of the new and I have a new desk lamp that also draws only 3W!

Result!

Energy Saving Halogen Replacements

When we first moved into our house 15 years ago, we installed halogen lighting in our hall.  Back then, electricity wasn’t quite so expensive, and we didn’t use the room that much anyway, and there weren’t that many options for recessed lighting.

We opted for a mains voltage system that could go on the existing dimmer switch, and therefore didn’t require expensive transformers for each light of the eight downlights.

Yesterday, I changed two of the lights over the table for the new Philips MASTER LEDspot PAR 20 MV dimmable LED lights.  I have to admit, I was ready to be disappointed, however the lights are very good.  Nearly as warm as the old lights, dimmable like the old lights, and fit in the sockets neatly as well.

I bought them from http://www.camelecws.co.uk/ in Cambridge.  I did get a quote from someone else for a discount of about £1.60 per lamp online, but I’d have had to buy 6 to get the discount.

Also on Amazon

 

The new lights have a slightly wider angle (40 degrees) but that was intentional, as the lighting was a bit too focused before anyway.

The downside?  These are really expensive (£26.34 each including VAT).

So, the break even calculations are:

£26.34 / £0.09 kWh = 293 kWh (amount of energy to break even at current prices)

293kWh / (50W – 7W) = 6813 hours (amount of time lights must be switched on to break even)

The old lamp has a life of 2500 hours, and they currently cost about £5.00 each, so it looks like we’d be replacing two of them during the payback period, so we put that back into the calculation:

(£26.34 - £10.00) / £0.09 kWh = 181 kWh

181 kWh / (50W – 7W) = 3693 hours

Now, we would like to leave these lights on in the evening from about 5pm until 10pm in the winter time, which probably averages out at 2 hours per night over the year.

3693 hours / 2  hours/day / 365 days/year  = 5 years.

That’s the payback for two of  the lights, but the 0ther 6 are more difficult, as they won’t be on nearly as often, probably averaging 20 minutes a day at best.  That makes it a 30 year payback, using the current levels of  lighting.

So the plan at the moment is to use up the stock of existing bulbs as they blow in the existing fixtures, and keep our fingers crossed that the prices come down over the next few years.

New energy saving gadgets ordered

Following on from today’s earlier post, I’m still searching for ways to make the house more efficient.

Lighting

We currently have some 240V, 50W halogen lighting in the hall, which generate 1000 candelas of light.  Now, there are 8 of these, so that’s 400W when they’re all switched on.

Today I ordered two Philips Master LEDlamps (these things aren’t cheap—over £25 each including VAT), but they do only draw 7W.  They’re also dimmable, and should fit in to the existing sockets.  If they don’t work out, I can still return them and get my money back.

Heating

In addition, I also ordered two electronic radiator control valves, that allow me to programmatically set the temperature a room should be at various times.  The target is the living room with the gas fire.  While the balanced flue fire appears to be around 90% efficient, it’s still easier to heat the lounge with the main central heating.

The plan is to not heat the room at all until 3PM, and then heat it to a base temperature until 8:30pm-ish, when the heating will switch off.  Normally, if we’re in the room, we’ll put on the fire to make it extra cosy, so if no-one’s in for any evening, it won’t keep heating.  When the fire’s on, it will warm the room sufficiently for the boiler to stop supplying heat to that room, and heat the rest of the house instead.

These devices aren’t cheap either (£25 each), and I need to drain the central heating system to add them, but as the current valves are leaking, I need to get a plumber in anyway.

Fingers crossed.  I can’t wait to see what effect these things have.