Saving electricity and CO2

Everything's gone a bit Dorothea McKellar

In the last few months Brisbane was underwater, Queensland and Victoria were ravaged by floods and everyone else seems to be getting heat waves, record rain, floods, plagues, bush fires or snow storms.

In the news this week there were two stories which really got our attention and have burnt themselves into our subconscious.  The first says that we're got little chance of keeping climate change to 2 degrees (the limit where things might still be manageable) and we're on track for 4 (genuine biblical proportions stuff). The other one is that electricity prices are going up again and are set to double every 5 years.  Eek, it's enough to drive you to despair. 

What can we do?  Well for the Joneses, it was time for us to do what we do best, be the Joneses we want to see in the world, and show people what we're doing (including the mandatory mistakes we make along the way so that you don't have to).

Today we went back to the drawing board to see what we could do, whether we'd done the right things and what else we can do.  We're pleased to report that we're not doing too bad and some things are paying off.  Here's a bunch of stuff we did to reduce our electricity consumption since we moved here nearly two years ago.

Tackling the big things first

The electricity in our part of the world comes from coal fired electricity which is relatively cheap in the short term but is one of the most carbon intensive forms of energy.  We wanted to get away from this.  

We looked at gas but our town doesn't have access to gas infrastructure, which means if we want gas we've got to buy it by the bottle and have it trucked in.  While possibly less carbon intensive than buying electricity, it just didn't resonate with us.

We paid the extra for Green Power and the first electricity bill was so outrageous that we just couldn't afford it.  Somehow we were consuming twice as much power as we had been at The Newtown Cottage.  We also were pretty sure that electricity companies have to have a mandatory portion of renewables, and by us paying for Green Power, all it was doing was paying them extra money to let them off the hook and didn't achieve much unless they'd already hit their targets.  Not a good option.  

We looked at solar panels, but our roof gets a lot of shade and doesn't get enough sun to make sense.

Also it seems that a large part of the increased cost of electricity is due to capacity limits of the grid during peak periods, so the real key is reducing demand.  Reducing our consumption without compromising our lifestyle was clearly the go. So the most sensible option was to invest time and money now in things which will save us time and money for many years to come (and lots of electricity and carbon emissions too).

You can spend a lot of time, effort and money on things which help a little, but don't really make much of a dent in your electricity consumption. So our first step was to focus on the big things first.  Here's a chart of the energy use of a 'typical' Aussie household. 

Source: http://yourhome.gov.au/technical/fs61.html

This gave us a good hint on where to start.

Now this data is for the typical household, so we looked at the big areas and if they looked inefficient at our place then we figured they were over the average.  Our two big ones were hot water, and heating and cooling, which we figured accounted for around 65% of our electricity bills and at least 50% of our emissions.

Hot water

We were horrified to see that hot water for the house came from two electric storage hot water systems, but because that there's no gas here we can understand why they were installed.  Given that this would be using at least 25% of our electricity this was the smartest place to start.

Needless to say we were really happy when the building report said they were at the end of their useful lives and needed replacing almost immediately.  We were also stoked to see there was still a hot water rebate available to get rid of inefficient hot water systems which would pick up about half of the cost.

As a rule of thumb traditional solar hot water systems trump everything else, followed by instantaneous gas.  Everything else is horribly inefficient.  We went with the best solar system we could afford, which was about double the price for a traditional Edwards/Solahart unit, but also twice as efficient and should last twice as long.  Other than in high use days in winter our hot water is pretty much free, even though we're in an area with two hours less daylight than most people due to being on the low side of a ridge to the north and having a lot of overcast days.

Savings: $180 per annum at current prices.  4-5 tonnes of CO2 - about the same as taking a light use hybird car off the road or planing 23 trees.

Was it worth it?  

Definitely for guilt reduction.  On a financial basis alone it'll pay for itself in about 8 years, and then keep on giving for another 20 or so.  Money well spent.  And we also got to meet Stephen from Viabuild who introduced us to permaculture, so that was a big bonus.

Would we do it differently next time

If we were city and strapped for cash we'd go instantaneous gas every time, but for where we are it was definitely the right move.  We'd definitely do it again.

Here's the skinny on our system.

Heating and cooling

Most of our appliances are reasonably efficient, we've got low wattage lightbulbs in and turn off the big appliances at the wall.  The computers are laptops.  We got rid of the big inefficient clunky hotplates that take 2 hours to heat and and cool and replaced with an efficient convection system. With this out of the way we figured the bulk of our energy use comes from heating and cooling.

The Joneshack is a 108 year old weatherboard house, built in the days before insulation. Weatherboard houses are great because you can cool the place down quickly in summer when the evening breeze comes in, but they're also hard to live in on really hot and cold days.

Mrs Jones was keen to put her mark on the new place.  We opted for ceiling fans with lights in them - they are stylish and functional, and besides, have you been able to find a tasteful light fitting anywhere that looks good with compact fluros?  The fans are great to avoid having to use the aircon, and the bright lights come in handy when the energy efficient floor lamps aren't bright enough.

We planted a nice deciduous tree in front of the main north facing windows to allow heat and light in during winter and keep it out in summer, and have trees shading the west side of the house to keep the hot afternoon sun out.  Deciduous fruit trees are growing in front of the east facing windows to deal with summer morning sun.  These will take some time but will be wonderful when established.

We moved in just before winter and were struck by how cold the house got compared to our previous place in Newtown.  There was no heating in the house - the previous owners had used fan heaters in every room, which means their power consumption must have been astronomical. This could not stand.  The Jones do not abide.

We looked at the various options, and decided that reverse cycle induction airconditioning was going to be the most cost effective option for heating and cooling.  As crazy as it sounds, induction systems can be highly efficient for heating because they extract heat from outside rather than having to create it from scratch.  Similarly they transfer heat outside of the house when in cooling mode and it means only shelling out cash once instead of having to buy a heater as well as a cooler.

In the short term while we were understanding how the house works, it meant we could turn the portable heaters off, saving a small fortune and oodles of CO2, and put the hot water bottles away and stop watching the steam coming off our breath while indoors.

But it still wasn't working.  We figured we must be losing heat out of the windows and doors.  So we sealed the doors, and put in some air tight window covers (we opted for wooden shutters, they have better thermal performance and for 50% more than the price of blinds, they look a lot better and last a lot longer).

Still no good.  We turned the laundry into an airlock so the dog can get in and out without a draft.

Still no good.  We got someone around to give us a quote of underfloor insulation, which is where we figured the last 15% might be, and it turned out that there was no insulation in the ceiling. We'd squandered our rebates on the hot water service, but for under $1000 we were able to get the Battman to do our roof with R4.0 pink batts.  Superb job, and what a difference that made.

Months later, it's still wasn't quite working out.  We'd been unable to find anyone to supply or install underfloor insulation and with our uneven joists and bearers, everything was a strange size and not square. We finally sourced and installed some Foilboard underfloor insulation in a few of the rooms and the difference was noticeable immediately in the rooms we'd done.  It's an awkward job, but pretty easy once we got the hang of it and one we should have got to earlier.  The guides say that there's only 15% energy efficiency to be picked up in insulating floors, but for us it feels like a lot more.

Was it worth it?  

Mrs Jones says definitely, she doesn't like extreme heat or cold much.  Mr Jones doesn't cope with humidity so he's happy too.  The reality is without the inverters, and insulation the place would have been unbearable during the winter and in the heatwave during the last few days.

Since installing all the kit, Mr and Mrs Jones are both spending nearly twice as much time at home and our power bills have remained more or less flat even when they should have jumped significantly.  The fact that someone is at home nearly all the time and we're still tracking below average household power use, even without gas is a pretty good outcome.

All up we've spent about $5,000.  It's hard to work out what our power bills might be without all the kit, but if we say an extra 10% on our bills, that's about $150-200 per annum, so about the same result as the hot water system, so about the same bang for buck ignoring rebates.

Would we do it differently next time

Your insulation is only as good as your biggest gap. In our case we learned this the hard way. We spent time looking for gaps, only to miss big ones. If you're going to do insulation, particularly in a weatherboard house, don't do it a bit at a time, do the lot at once.  Also if you've got an attic, don't overlook this, it needs to also be insulated, including the floor and roof cavity.

If we were a bit more confident we would have put a wood stove and bricked around it.  This would have given more thermal mass to maintain the temperature in the house rather than just heating or cooling the air, and the stove could cook, heat the house and give the hot water system a boost in winter.  

We'd probably spend the extra and get an induction cooktop instead of a ceramic one.

Summary

We pretty much did a lot of the text book things to our house, and they all seem to work, but have taken us time to get right.  We'd agree with the text books though:

1. Change to solar hot water, or instantaneous gas if its an option and you're short of cash.

2. Deciduous trees as first option around the house to deal with the summer heat while allowing winter sun in - they're the cheapest option.  If we were to do it again, we'd spend more and get more established trees.

3. Get as much thermal mass into the centre of your house as you can (which we didn't do), and have as little thermal mass around the outside of your house as you can (check).

4. Insulate the house well (in progress)

5. Efficient heating and cooling solutions.

This should give you the biggest bang for buck while you're also tinkering around the edges.

One of the best resources we've found is the Your Home Technical Manual and the fact sheets are available free online.  We found it invaluable, to the point that we could talk rings around the Green Home assessors.  We'd suggest having a really good look at it.  It's clear, simple and very very useful.

The Joneses

Be the Joneses you want to see in the world

Everything you ever wanted to know about hot water and more

This is the story of the Jones family and our choices of hot water.  We've had a lot of people ask us about it, which means some people are thinking about keeping up with these Jonses.  The experiment is working!


In this article we'll take you through how we made our decisions, why these may or may not be the right decisions for you and what our life's like with a solar evacuated tube system on our roof.


Energy options, constraints & greenhouse gases

The Jones family lives in an area where there's no natural gas connected, so for energy here we've got several options:

1. Use coal fired power which is relatively cheap but is a huge contributor to global warming
2. Pay a bit extra to buy Greenpower from the grid, but also knowing that a lot of energy gets lost between where it is generated and our front gate
3. Have natural gas delivered which is less CO2 intensive than coal, but has to be trucked to our gate in diesel trucks
4. Generate as much as we can on site.

Naturally we liked option 4, but needed also to be realistic with living within our means.

When we first arrived at Jones Manor, there were two off-peak electric storage systems, totalling just under 200 litres.  This would have made perfect sense at the time. Off-peak is cheaper and can be delivered within existing capacity of the grid, and at the time, global warming wasn't well understood and energy saving options weren't as viable as they are today.  Great case for a retrofit.

So you can imagine our delight when our building report told us our old electric systems were nearing the end of their useful lives, were at risk of failing and would need to be replaced.  Solar water rebates were also available which was going to help a lot (these are still available, but not as generous as they were).  Considering that hot water is the largest single source of energy use and greenhouse gas emissions for most homes (around 20-25 per cent of household emissions), this seemed to be a great place to start and solar was the obvious choice.

Choosing a hot water system

We did our research - the usual places: ask your friends, ask Google, ask your Dad, talk to some providers, try and cut through their spin and bias and then try and find some authoritative sources and buyers guides.  In our case the most useful sources were the Your Home Technical Manual, the Alternative Technology Association and Mr Jones' Dad.  (Yes Jones Sr, we did ask you first and all our research proved you right, but don't get a big head about it).

We did some comparisons between solar flat panels (the types that have been an Australian icon for many years) and the new fangled evacuated tubes which hit the market in the last few years.  What we consistently heard from a number of sources was the solar evaluated tubes were nearly twice the price of flat panels, but were worth the extra money because:

1. They are nearly twice as efficient, which means you don't have to run your coal powered electric booster as much on cloudy days
2. The tubes handle hail better and can be replaced one tube at a time if they get damaged
3. A stainless steel tank with the system should last for a good 25 years, which could be twice as long as normal.

Knowing that the flat panel system on Mr Jones dad's house was a disappointment because it's booster seems to be running most of the time, and also wanting something to last until the rest of Mr Jones beard turns grey, we decided to give this new fangled contraption a go.

Our phone calls and background checks seemed to indicate Apricus was the brand to go with, so we gave them a call and they introduced us to our new mate Stephen from Viabuild who was the local agent and experienced guru on the product.  Now you've got to be careful with a bloke like Stephen, because you'll quickly realise that perhaps you don't know everything about sustainability, and next thing you know Mr Jones will be doing a Permaculture Design Certificate and wanting to know how to build an earthship and live in the desert, but that's another story.

Fit for purpose

Anyway, Stephen took us through it all and looked at our limiting factors.  There were four in particular:

1. A ridge line and huge Lilly Pilly tree to the North-East which gives us about 1 less hour of direct sun in the mornings
2. A ridge line and large trees to the North-West which give us about 2 less hours of direct sun in the afternoon
3. Heritage limitations which mean the tubes must be flat, and slightly sub-optimally placed
4. Practicalities which mean the tank needed to be on the ground instead of in the roof.

Our new fangled solar tubes. mid-afternoon, winter.

As a result of this we decided to go with a 30 tube array and a 250L stainless steel tank, which is enough for a reasonably sized family with minimal boosting, even in winter. And for a couple it should require nearly no boosting at all, even on cloudy days in winter.  

The reality - what's it actually like?

We've had our system nearly 12 months now and we love it.

Our configuration means we've got a pump and a controller, which is really clever.  The controller measures the temperature in the tank, and also in the tubes on the roof.  When the tubes are 8 degrees hotter than our tank, the pump turns on and sends water from the bottom of the tank (coldest part) to the tubes on the roof and brings back hot water.  If there is only a 2 degree difference, it turns itself off, and waits for the tubes to get hot again.

There is a big display on the controller which shows these temperatures, which means most males and anyone techy / geeky will be out looking at it every few minutes for a month or so and probably keep doing this for the first year or two.  It's a bit like watching the display on a Prius and getting excited about braking... actually, now that I mention it...  {Mr Jones wanders outside to take photos as an excuse to look at the display and see what the system is doing} 

Controller 12 months on with a few cobwebs

Sorry about that, back now, but here's a two photos.  It's 2pm which means we've got another hour or two of direct sunlight to go.  As you an see, the temperature on the roof is 57 degrees, and the ambient temperature on the back verandah (below) is 15 degrees.  It's a sunny winter's day here, and the bottom of the tank was at around 15 degrees this morning because we deliberately ran the system down.  The bottom of our tank is 54 degrees, which means the whole thing is toasty warm and an ideal temperature, all free from the sun.  

Ambient temperature in the shade

So the important thing is whether we actually saved all that electricity or not.  The answer to this is yes and no.

As we indicated before, our placement is suboptimal.  The unit is laid fairly flat which means we're getting around 8-10% less input than we'd normally get.  Also because we're on the low side of a ridge, we're getting around 5-6 hours of direct sun instead of 9-10, so deduct another 40% for that.  And lastly this is a very cloudy place, so it's overcast regularly which brings most things to a slow churn, so it seems the gods are against us our little experiment and we should be doomed to failure.

But, we didn't fail, it's been a great success.  Take today for example, it's a winter's day, and our hot water for the day will be free apart from running the pump (which is negligible energy and cost). Free. No booster like Mr Jones' dad.  Free.  Woohoo.

In spring through summer and autumn, we turn the booster off entirely when there's just Mr & Ms Jones at home and only turn it back on on really cold cloudy days or when we've got guests.  The system can keep up with sort of behaviour except when we get a few cloudy days in a row.

So if every day was like today, the system would pay for itself in 5-10 years, and still keep giving for another 15 or so, so that's not bad for a system which is severely handicapped by where it's located.  It's also worth noting that electricity prices will double every 5-10 years and continue to heat the planet, so it starts becoming an obvious thing to do.

Also it's good to know that because the tank is stratified and shows the coldest part, which means even when it's really cold in the tank (say 15 degrees), you've probably still got enough for two hot showers from the top half.  And on a warm day, we've clocked 146 degrees on the roof (the pump shuts off to protect itself above 83 degrees).

So these are the tangible bits, and the stuff you need to know so that you're not kidding yourself.  But for us there was something much more important.  

The moment we installed the tank, was the moment we became the Jonses.  

We live on a street with a lot of foot traffic on it, and at least a dozen people have stopped to ask us about our disco tubes on our roof.  We also put a few pictures on Facebook and people asked us questions. We were able to tell them all about it and now some are looking into it closely, and are doing it too, or had already done it.  It was at this point we realised how much impact you can have by being the new Jonses or following some other Jonses.  One day we might even be able to spell Jonses.

Lessons and what we'd do differently

If we had our time again we'd probably consider a thermal siphon, which is basically a fancy name for having a tank on/in your roof that self-circulates without needing a pump.  Simply, hot water rises and if your tank is above your panels you don't need a pump.  If your tank is below your panels, you do need a pump, which means moving parts and a small amount of energy to run the system.

Why would we do this?  Well our pump died after 11 months, just gave up the ghost, and we wouldn't have noticed if our power bill didn't look unusually high, so it might have been dead for a while.  Having said that, we still had hot water because the off-peak booster kicked in, but we generated a few black balloons without realising it.  The Apricus team were great, replaced and installed a new pump in less than a week at no charge and it seems we're one of their only pumps to ever have failed, so hopefully this is an isolated problem.  This is all pretty impressive for new fangled technology.  

Now if we had a tank on/in the roof, there would have been no pump, and nothing to die on us, which is nice to know.  But it also might have meant reinforcing the roof to carry the extra 250 kg of weight, and there wouldn't have been a cool gadget to look at {Mr Jones leaves the room again...}.  Quick update from Mr Jones, the tank has increased in temperature by 3 degrees in the last 30 minutes.  How cool is that?

The Jonses

Be the Jonses you want to see in the world

Useful references for digging deeper

Your Home guide - what type of system should I get?
Your Home Technical Manual - Hot water
Hills fact sheet: solar tubes vs flat panels