My Online Diary

Energy Use I Am Directly Responsible For

2009-08-25T21:19:00.000-07:00

Phil Scadden, a Dunedin based scientist, recently wrote "Sustainable Energy - without all the hot air: a New Zealand Perspective" using data from the Ministry of Economic Development, Energy Efficiency and Conservation Authority and the Electricity Commission. More: http://withouthotair.com/ and http://www.inference.phy.cam.ac.uk/wiki/sustainable/en/index.php/NZ

The report includes this chart:

Energy Use You Are Directly Responsible For

So Stuff, Cars and Planes makes up 70% of energy use I am personally able to do something about. I need to be thinking more about "Stuff".

1. Stuff 39% - We try not to buy much stuff, and when we do we try to buy second hand. TradeMe is great for that. We try to limit our purchases to the Wellington region.
2. Cars 25% - We sold our Toyota 1400 back in 2004. Since then we've managed to car share, hire, do without, use public transport, taxis and cycle.
3. Planes 15% - We're trying not to fly. We haven't been on a long haul flight since 2005.
4. Food 12% - Since Adam was born in Oct 2007 either Michelle or I have been at home every day of the week. So we're doing a lot more hm cooking. I'm not what the energy implications of that are. I don't think we've done anything to reduce our food related energy budget.
5. Home energy 9% - Most of this blog has been about my home energy projects - which has been fun.

Pelmets

2009-05-27T03:32:00.000-07:00

I'm now working on installing pelmet above all the curtains. Pelmets help stop/reduce hot air being "sucked" behind the curtains as the cold air next to the glass falls to the floor. It also helps that our curtains drop all the way to the floor.

This is my first version - unpainted at this stage. That's the cheap heat pump I installed back in 2004 - still chugging along, keeping us warm. It's not as quiet as newer/fancy ones - but it does keep us warm.

More detail on my pelmet construction here.

Cheers, Paul

Interim HERS assessment

2008-03-25T01:49:00.000-07:00

Here's the interim certificate (2 meg), - this is interim until EECA get all of the star rating bands confirmed and the room heating star calculator confirmed, as soon as these become available updated certificates will be issued.

HERS assessment: 6.5 stars

2008-02-22T01:07:00.000-08:00

My house has a 6.5 star HERS rating.

The Home Energy Rating Scheme is a new programme the government has started (this month) to provide standards based home energy audits. The assessments are carried out by nationally credited assessors.

My assessment was done by Steve is from Ecosphere. He spent 30 minutes measuring the house dimensions, walls, foot print and windows and documenting the insulation, space heating and hot water heating we've got. Then a few hours back at the office feeding the data into the special HERS software, plus some more to write up a list of improvement recommendations.

He says; "your house has a 6.5 star rating [out of 10] which is exceptional considering the age of your house. That second layer of insulation in your ceiling was worth half a star."

"...the only realistic recommendations that could be made for your house were, new sealed double glazed windows (which would save you approximately $50 a year in heating costs), and replacing your heatpump with a highly efficient 6 star rated unit, which if used in conjunction with a low voltage heat transfer system would be able to save you more."

It's nice to have external validation for what I've done. The windows were my main (low priority) insulation project going forward - so it looks like I'm on the right track.

It would be nice to get it up to 7 stars.

Here's the interim HERS report for my house.

End of year update

2007-12-20T01:36:00.000-08:00

It looks like our energy usage will end up about 5400 Units, which is more than the 5000 Units of the last two years. Bummer.

The first half of the year went really well. We were tracking at or below all other years. But then on the 3rd of October, on a dark and stormy night, we had a baby at home. We ran the heat-pump almost 24 hrs a day for about a week. And, of course, we started washing nappies almost every day. That made October almost as power hungry a month as mid winter June/July.

Once again - it's really hard to tell what effect my insulation efforts have had. There's no blindingly obvious reduction in power. But... we're now a family of three and still we're going to be well under the 8000 Units that the government uses to define a "low user" of electricity. That's not bad considering all our home energy usage is electric - we don't use gas or wood. (Even the lawns are mown with an electric mower.)

We finally switched to Meridian last month. Once we'd transitioned from pre-pay to standard billing with Genesis, it was easy to switch providers - just a phone call did the trick. So now all our home energy usage is electricity generated form "renewable" sources (mostly hydro).

Last weekend I finished putting two 1000 litre rain tanks in behind the garage. The tanks cost $85 each from Pacific Wallcoverings in Porirua. On Tuesday a southerly came through and gave me 500 litres of rainwater. I'll be using this water for the garden over summer.

My next plan is to add another two 1000 litre tanks behind the garage and work out some way to use the water for the toilet and clothes washer. I haven't thought about greywater yet.

Well... actually, I have... and I can't think of a clever/cheap way to do it. It may be one of those tasks that is best left to experts.

Upgraded washing machine

2007-10-08T01:31:00.000-07:00

I've just replaced our old cheap washing machine with a 2001 Indesit WD 11 front loading washer dryer. This should save some power and water.

But... Michelle and I have just had a baby - which will raise our energy usage a lot.

Spring update

2007-09-02T02:28:00.000-07:00

We're starting to get some good solar hot water now. Today we got the hot water cylinder up to 55 degrees C.

The solar PV is going very strong now as the day get longer. The charge hasn't been below 97% for weeks. The PV system is currently driving the weather station and it's data logging laptop. Over summer I might be able to switch to running the web server. I'm just a little worried my 4 Trojan T104 batteries are not enough for that load. Ideally I should add another 4 to give the PV system enough storage to last a few days of grey weather.

My purchase/wish list now is:

Add 2 or 4 more Trojan T104's
Add another 80 Watt PV panel (to bring the total to 4 panels)
Upgrade to a 24 volt input true sine wave 1000 Watt output inverter

Step 3 means I can reconfigure the PV panel wiring to 24 volts (2 strings of 2 panels) - which will reduce the DC voltage lose over the wires.

Then I'll be ready to power the web server from solar panels all year round.

The plastic double glazing is now starting to show it's weak points:

if you tape the plastic out to the edge of the window frame it looks better, but in heavy winds the plastic edges start to "wheeze". They make a sound like a lamb bleating 100m away. Not entirely unpleasant - mostly odd.
if the window frame has any cracks in the joints - it will let in moist air. The moisture builds up and does not escape. I've got this on a sash window that I plan to restore this coming summer. I don't have this problem on the sash windows I've already restored.

The LED spotlight is working so well I jumped online to order some more. My main source was out of stock so I hunted around and found a Chinese source for 8Watt (equivalent to about 100Watts) warm white LED spotlights, for only US$30 each (plus shipping). I got 2. They are less bright than the first ones - but have a "warmer" light (ie yellower). They seem to be working fine too.

I may buy another of the previous type when they are available. Then I'll use the warm white ones out front, and the stronger cool whites on the garage overlooking the back yard and garden.

One more thing - my power company Genesis, raised our prices last month, almost doubling the line charge. Plus Genesis generates a fair bit of it's power from non-renewable sources (eg coal power stations) - so we'll switch to Meridian soon.

Cheers, Paul
paul at kennett dot co dot nz

Installed a rangehood in the kitchen

2007-07-10T03:40:00.000-07:00

I installed a rangehood extractor fan over the oven/electric elements on Sunday. This should reduce the amount of condensation in the main living area. I bought a second hand Robinhood Grange II for $60. After reading the website I noticed that this model is one of their noisiest, 65 db - doh!

So I took some spare sound dampening foam and cloth that I used to have in my web server closet and glued that inside the unit. Which seems to have helped "a bit". (Shame I didn't have a db meter.)

We cooked salmon on Monday night and that didn't stink the house out too much.

The only other downside is the unit has two 40 Watt lamps in it. I'll see if I can get lower powered replacements - it seems like a good situation for white LED's maybe.

LED spotlights

2007-06-28T21:55:00.000-07:00

I'm testing an LED spotlight from EcoInnovation It comes in the form of a standard screw-in spotlight and contains over 100 LED's. It draws 8 Watts and produces roughly the same light output as a standard 100 Watt spotlight.

It cost NZ$118 - which aint cheap, but LED lights are supposed to last up to 8 times longer (we'll see). The light is at the blue end of the "white" spectrum.

I'm happy enough with it to replace the rest of my spotlights.

Cheap double glazing options: one month later

2007-06-13T15:48:00.000-07:00

I've been trying three different double glazing options now for about a month. And we're now finally starting to get some cold weather (although we haven't had a lot of rain all year).

The "real" double glazed unit is working fine. On a very cold morning the is sometimes a bit of condensation on the room face of the window (the side you can touch when inside the room). I'm waiting for a nasty southernly with driving rain to see how well the way I've fitted it works, but from a insulation perspective it seems to work fine. The double glazed unit, from Ultra Glass cost $110 for a single 512mmx1250mm window.

The cheap acetate (plastic) extra layer seems to work just as well. But cost about $5. I've read that they last 1-2 years. Not sure what happens to them after that time. On a very cold morning there is sometimes a little condensation on the room face of the window (in side you can touch when inside the room). One of the sash windows also has condensation in betweeen the glass and acetate so I'm assuming there is a gap in the putty holding the glass in the frame. I plan to renovate this window and replace this glass with laminated glass sometime - I won't doubel glaze it because it's on the (sunny) north side and a double glazed sash window would be heavy and cumbersome. The plastic film is available from Community Energy Action in Christchurch and here's some other comments about it.

The bubble wrap works OK - it does gather some condensation on very cold mornings. Given that the price is not much better than the acetate option, and the look is not appreciated by some observers... I will favour the first two options.

First "real" double glazed window

2007-05-12T05:16:00.000-07:00

Installed a double glazed unit into one of the lounge south windows today.

It's a 4mm, 4mm glazed unit with 16mm spacer, built by UltraGlass for $110 (512mmx1250mm in size).

I removed the existing window frame
removed the three panes and two muntins
routed the inside space to allow the much thicker double glazed unit (24mm) to fit
painted window frame
used wood beading to fit window in place
reattached window.

This window is one of three. The second window has acetate on it and the third is unchanged. In the mornings there is condensation on the standard window and none no either of the other two.

Cheap double glazing

2007-04-28T04:57:00.000-07:00

I've started experimenting with double glazing. I've chosen three options:

bubble wrap
acetate (plastic stuck on the window frame with doubel sided tape)
retro fitting double glazing units

I'll report more as results come in.

Finished insulating walls

2007-03-10T04:55:00.000-08:00

Yep - it's all done. (Except for under 3 windows.) Read the full details on the cheap wall insulation project.

New web server installed, but adds 2 kWh per day!

2007-02-01T04:48:00.000-08:00

Just upgraded the machine that runs my home web server to a second hand Compaq Proliant 460 with dual RAID array drives. But it's noisy as hell and a real power hog. The old machine was a no-name P3 box that used less than a third of that.

Looks like it may suck up as much power as I save on the solar water heater!

Doh! This is a classic problem that has been warned about concerning energy efficiency - people tend to use up any savings they make "to improve their lifestyle". I'm just as guilty.

Starting wall insulation project

2006-12-28T04:45:00.000-08:00

Have started blowing polystyrene beads into the south facing wall for insulation.

It's a lot of fun.

Solar hot water

2006-06-06T04:43:00.000-07:00

Finally got the solar hot water system up and running.

Of course, we're not going to see much use out of it till at least spring.

"Upgraded" to more expensive power

2006-03-28T04:32:00.000-08:00

When we moved into the house we found it was connected via pre-pay system. You go to your local Blockbuster video store and buy "power" from them with $20-$100. They give you a 16 digit number which you then punch into a keypad next to your power meter at home.

It sounds a bit micky-mouse, but had the advantage that it (a) gave a digital usage reading and (b) didn't include a daily "line charge".

Eventually the power company (Genesis) decided to upgrade it systems to rectify that. So today we are paying 33.750 cents/day plus 17.500 cents/unit, but there giving us $15 per month to keep our custom. (My plan is to stay 12 months then switch to Meridian who generate power using more "renewable" energy sources.)

The other benefit of this new system is that it provides an indoor control-monitor panel - so I don't have to read the meter out in the rain anymore.

Solar powered house lights

2005-07-06T04:27:00.000-07:00

Just finished installing my baby solar power system.

I've got a single 80Watt PV panel, connected to a charge controller, connected to 4 car batteries, which drive a small 12DC to 230AC invertor. Which then runs all the CFL lights in the house.

Doing this in mid-winter doesn't make much sense but - really - I'm just playing with this stuff.

Upgraded water heating insulation

2004-12-05T04:24:00.000-08:00

I used some left-over sissilation (aluminium foil) to double wrap the water cylinder in two layers of blanket/foil combo. That should give about as much insulation as is practical.

Heat pump installed

2004-09-06T04:20:00.000-07:00

Just installed the answer to our heating needs. It's a cheap Chinese no-name unit I baught via TradeMe. I installed it myself and had an air-conditioning contractor "commission" it. That meant they evacuated the tube finished off the tubing connections. So it should work as well as it it able to.

It should mean lower power usage - see my daily power usage data for the results.

Peak electricity usage today

2004-08-18T04:13:00.000-07:00

[This is a retro-posting from 19 May 2007.]

Today was the most power hungry day we've ever had. Following the new theory of heating the spaces not the occupants - we had all three electric heaters on full blast to keep us warm.

The data was: outside temp 7.6 degrees C, inside temp 21.4 degrees C, 68.6 electricity units used costing $10.49. Ouch!

Home energy efficiency audit

2004-08-04T04:04:00.000-07:00

We had Barry from Negawatt Resources Ltd come in and do a home energy audit for us.

Ceiling insulation is more effective if it is layed over the rafters, not between them. The rafter act as a bit of a thermal conductor.
it's healthier for the home and it's occupants if you heat the spaces people live in rather than try to heat the people directly (by huddling infront of a heater). Ideally leave most of the interior doors open and heat all the main rooms.
We should get rid of the 3 bar electric heater we were using in the lounge and buy oil filled electrix heaters with thermostats. And don't buy the small ones.
Better to install a clothes dryer than dry cloths on a rack inside. Better still - dry clothes outside.

Temperature monitoring

2004-08-01T03:58:00.000-07:00

Baught a $35 indoor/outdoor temp plus relative humidity gauge from Dick Smith today. I'll add that data to my daily power usage spreadsheet.

Underfloor insulation

2004-07-27T03:55:00.000-07:00

Finished putting polystyrene blocks and sissilation (aluminium foil) under the floor.

It was not a fun job - but at least it's done now.

Curtains up

2004-04-17T03:54:00.000-07:00

Got all the curtains up today.

They are double layer thermal drapes.