Thursday, 19 March 2015

Futurefitting begins! LED lighting

We've not wasted any time in moving ahead with our plans for home improvements. So far we have had people round to give us quotes on solar panels and solid wall insulation on the energy efficiency side of things. And curtain measuring, surveying for removing a wall (and getting a new bathroom), and last will making on the general improvements / life admin side. So plans are afoot.

But I've actually already finished my first bit of futurefitting, I started the very first week we moved in to the house. And that was by installing LED lighting in every room and appliance in the house (with 2 exceptions).

The first thing to do when you want to do this is to take an inventory of all the lightbulbs in the house that you want to change. You basically need to know the rough size and shape (globe bulb, mini-globe, candle, spotlight, etc) and, more importantly, the fitting size that the bulb is. You don't want to spend a lot of money on a bunch of screw fitting bulbs to find out all the fixtures in your house are bayonet type.

I won't go in to all the sizes and types here (E27 and B22 are the most common, but there are lots more). But if you need help, here is the guide I used when I was going through this process.

So here is my original list:
Big bedroom: B22 CFL bulb (11 watt)
Medium bedroom: E27 CFL bulb (11 watt)
Small bedroom: B22 CFL bulb (11 watt)
Stairs, top: B22 CFL bulb (11 watt)
Stairs, bottom: B22 CFL bulb (11 watt)
Living room: 3 x E14 Candle bulbs. 1 incandescent (60 watt), 2 halogen (42 watt each)
Bathroom: A CFL in a really weird shape (not a bulb shape), housed inside a plastic box that I can't get open
Kitchen: B22 CFL bulb (11 watt)
Then lamps & appliances:
Oven extractor hood: 2 x E14 incandescent Candle bulbs (40 watt each)
Fridge: E14 mini globe? halogen (15 watt)
Living room lamp: Missing a bulb
Medium bedroom lamp: E27 incandescent bulb (60 watt)
Big bedroom bedside lamp: B15 incandescent pygmy bulb (15 watt)

So if you add all that up it comes to a total of 380 watts.

So I went over and had a look at the range of LEDs they had available at Ecotopia. Not knowing where to start and not wanting to make any expensive mistakes, I started by buying one bulb for the medium bedroom (an E27 fitting) so we could test it before making any other purchases. Now, as most of the bulbs in the house are CFL, I didn't know what incandescent equivalent to shop for (most LED bulbs will say X watts, equivalent to X watts incandescent). So I took a guess and bought a 60 watt replacement bulb, the £8.99 8.2 watt 806 lumen Integral LED bulb.

After waiting in anticipation for the bulb to arrive, I eagerly changed the bulbs over and flicked the light switch. And Anne instantly said it was too bright...

The problem is that in the old days you bought a bulb based on it's wattage. That was the indication of how bright it was. Now, with energy saving bulbs a 11 watt bulb can give out the same amount of light (or more) than an 100 watt bulb. So buying bulbs based on watts, or even equivalent wattage, doesn't work. So we're all meant to be buying bulbs based on their lumen rating (see this handy video from the US government). But how bright is a lumen? or 500 lumens? I had no idea. And old bulbs do not have this information written on the side of them (new bulbs do), so you can't use them to help guide your purchase.

So next I bought a bulb that was meant to be a 40 watt equivalent, the £6.49 4.6 watt 470 lumen Integral LED bulb. We gave this a try and Anne and I were both happy with it. So from there I had a rough understanding of how many lumens we wanted.

So as not to waste the bulb we stuck the 806 lumen bulb in the living room lamp (which was missing a bulb anyway). Then we also got an 806 lumen bulb for the kitchen (where Anne was happy with a brighter bulb). All the other rooms in the house got 470 lumen bulbs, except the bathroom which I left because I couldn't unscrew the cover, and the living room which I replaced the 3 candle bulbs with 3 250 lumen LED candles. I also used 2 more 250 lumen candles in the oven extractor hood and a 250 lumen LED mini globe for the medium bedroom lamp.

That left only the fridge and the big bedroom's bedside table lamp.

Now, I couldn't work out if you had to have a special kind of LED bulb to put in the fridge to put up with the cold temperatures. I couldn't find a definitive answer either way, but decided to get one just to be on the safe side. There aren't many options out there, I could only find bulbs from Tesco, Screwfix and eBay. In the end I went with the Osram bulb from Screwfix. The main reason for this was because every bulb we'd bought so far had been warm white 2,700 - 3,000 kelvin. And I wanted to see what a cool white (5,500 kelvin) bulb would look like. And boy am I glad I did. Now when we open the fridge it looks like one of those 80's sci-fi films when the alien spaceship opensand the really otherworldly light comes shining out. (I'm easily amused)

That left only the bedside lamp. Now this was impossible to find a bulb for. Firstly it's a mini-bayonet (B15) fitting, which is quite uncommon, and very  few people seem to be selling LED bulbs with this fitting. Secondly it's a very small bulb, smaller than a mini globe. After a lot of searching around I found out it's called a pygmy bulb... But then to make matters worse, our lamp has to light switch states, on full brightness, or half brightness. So I needed a dimmable bulb. Dimmable LED bulbs are harder to find than non-dimmable, but a dimmable B15 pygmy bulb is impossible.

In the end I thought I would chance it and bought a non-dimmable bulb for £7.60 from tp24 I found on ebay. It arrived and I got all excited again that my LED upgrade was finished (other than the stubborn bathroom light). But when I tried it the bulb didn't come on. I tried both brightness settings on the lamp, nothing. So I put the old bulb back in and kind of gave up on this one. The lamp is so old I don't think I'm going to find a suitable bulb.

So taking stock here's how the lighting situation in the house looks now:
Big bedroom: £6.49 LED (4.6 watt)
Medium bedroom: £6.49 LED (4.6 watt)
Small bedroom: £6.49 LED (4.6 watt)
Stairs, top: £6.49 LED (4.6 watt)
Stairs, bottom: £6.49 LED (4.6 watt)
Living room: 3 x £5.99 LED (2.9 watt each)
Bathroom: Still has the same weird CFL with mystery wattage
Kitchen: £9.99 LED (8.2 watt)
Then lamps & appliances:
Oven extractor hood: 2 x £5.99 LED (2.9 watt each)
Fridge: £6.99 LED (1.4 watt)
Living room lamp: £9.99 LED (8.2 watt) - As this was missing a bulb, this is the only fitting where energy consumption has actually increased...
Medium bedroom lamp: £5.99 (3.5 watt)
Big bedroom bedside lamp: Still has it's old 15 watt bulb in it as my £7.60 (3 watt) LED bulb didn't work.

So in total I spent £102.96 to reduce the watts from 380 to 73.8. That's less than a fifth of the old energy usage.

As to how long it will take me to earn back the money spent on bulbs from the savings made on our electricity bills, I have no idea. I could work it our based on the average model of using each bulb 3 hours a day and the unit (kWh) cost of our electricity. But to be honest, I'm not really interested. I know the payback time is probably about a year (two at the most). But these bulbs should last for 15 to 25 years (depending on the bulb), so I know I'll be saving loads over the lifetime of the bulbs.

So as I've given up on finding a dimmable B15 pygmy bulb for the bedside lamp (but if you ever see one, let me know!), all I have to do now is replace the light in the bathroom and I can consider my first futurefitting job complete. We're actually planning to completely redo the bathroom (if we can afford it), so I'll probably just change the light fitting then. As it's a CFL I can live with it for now.

Monday, 9 March 2015

The EPC. Taking stock and the start of a plan

So. Now we've moved in to our new house and (mostly... somewhat) unpacked, the next question is where to get started with our futurefitting.

And true to form, I'm going to use the EPC that we received from the sellers to guide my choices (somewhat). So here's what we've got:


So the house got a mid-range D rating. Note this EPC was carried out in October 2012, and we actually bought the house in February 2015, so it may not be exactly up to date. But it's good enough to get started with.

The important thing is that it says there is scope to vastly improve the house up to a high B rating, just under an A. This is good, as we had looked at other houses that were E rated with potential to only get to C...

Another good thing is that the house is already rated D, which is the minimum rating needed to collect FiTs (feed in tarrifs) on any electricity you generate from solar panels. And as our roof is south east facing, thankfully the house is suitable for solar panels.

So lets take a look at what the suggestions were to bring the house up to a high B:


Also, not included in the table, but listed under "Alternative measures" was "Air or ground source heat pump".

Now in my very second blog post I laid out my plan of action on my then unknown house as being:

1. Solar panels
2. Wind turbine
3. Ground source heat pump
4. Electric oven (with induction hobs)
5. Low-e double glazing
6. Loft insulation
7. Cavity wall insulation
8. Draught proofing
9. LED lighting

Now this original theoretical plan is actually pretty accurate. But some of it doesn't fit this house so the following alterations need to be made:

Change 1: The house has double glazing, so this is no longer needed. Obviously as the windows get older they will need replacing, in which case maybe we could actually get triple glazing. According to the Centre for Sustainable Energy:

"The typical lifetime of double glazing is around 20 years. Over time, the gas within the panes will gradually evaporate at an estimated rate of 0.5-1% per year."

Now, the sellers told us the double glazing was installed in 2012. But they didn't provide any paperwork proving this, as they said they had lost it. Now, assuming we can trust them (I'm not sure we can, but let's give the benefit of the doubt here) this means we don't really need to change the windows until 2032. (I'll be 50 years old) 

Change 2: We can't get cavity wall insulation as the house has solid walls! (my worst nightmare). We estimate it was built in the 1920s, and cavity walls didn't really hit the mainstream until 1930 onwards. So we'll have to get solid wall insulation, which is far more expensive. But there are two bright sides. Firstly, the house is mid terrace, so we only need to insulate the front and the back (I'm already leaning towards external insulation), and secondly, the green tick in the EPC means this is likely to be fully financed under the Green Deal.

Change 3: The house already has loft insulation 200mm thick. This isn't as good as the recommended 270mm, but it's a start and means this might not be an urgent change for us. But we do need more storage space and the loft hasn't got loft flooring laid down yet, so if we do this in the near future (merely so we can store our crap up there), then it would be worth upgrading the insulation at the same time.

Change 4: The house doesn't really need draughtproofing. It's got a draught excluder on the letterbox and round the front door. (And the back door is double glazed). So this can be dropped in favour of floor insulation and heating controls.

Change 5: Maybe a new boiler is needed. Maybe not. The EPC says that it is needed (a condensing boiler), so it probably is. But we recently had both pre-paid gas and electricity meters removed and replaced with normal meters. The man that changed our gas meter took a look at our boiler and said it was "like an Audi, but an old Audi."
I think this was a compliment and he seemed to be saying it was in good nick (It's not actually an Audi, they don't make boilers. It's a Vaillant).

Go Compare says:

"Boilers last up to 15 years. If yours is reaching that age, then think about saving for a new one."
and
"Annual services are essential."

Now, I've looked all over the boiler (without opening it up) and I can't see any information on what model the boiler is, or how old it is. So it could be ancient. But judging by the dust on it, I'm pretty sure it hasn't been serviced in a couple of years. So I think maybe we get it serviced at the very least. What is worrying it that from 2005 it became mandatory for new boilers to be condensing boilers. So if ours is not a condensing boiler (as the EPC seems to suggest) this means our boiler must be at least 10 years old, maybe older! So maybe we do need to look in to replacing it sooner than later.

So taking all of these in to account the new plan of action looks like this:

1. Solar panels
2. Wind turbine
3. Ground source heat pump
4. Electric oven (with induction hobs)
5. Heating controls (room thermostat & TRVs)
6. Loft insulation (upgrade to 270mm)
7. Solid wall insulation
8. Floor insulation
9. LED lighting
10. New boiler (at some point)

It's good to have something to aim for.
Now, the easiest and cheapest of these is the LED lighting. So I've already made quite a lot of headway on this. (the subject of my next post)

But that doesn't mean we can't work on a few of them at once. Tomorrow afternoon we have someone from Better Energy coming over to probably give us the hard sell on solar panels. And when we last visited Ikea I looked in to their solar panel partnership with Hanergy.

More soon!

Friday, 6 March 2015

I'm back!

After a long hiatus I'm back and ready to start futurefitting once again.

The reason for such a long delay was because there were lots of issues with the first step on my retro-fitting plan: First find a house to move in to.

After 3 accepted offers that turned in to long protracted ordeals that all fell through just as we were about to exchange contracts, we finally got lucky on our 4th attempt. If your definition of "got lucky" is another 6 month ordeal, where we failed to exchange contracts on the planned day because one of the sellers was diagnosed with cancer!

Anyway, having moved in a month ago we're finally settled enough (but not unpacked) to get started. So an update on my LED lighting situation is imminent.

Watch this space!

Tuesday, 31 December 2013

Insulationzzz



As the weather starts to turn and it becomes pretty cold during the day (rather than just at night) it’s time to talk about insulation.

For me this is probably the least interesting of all the subjects I’ll be covering in my quest for the energy efficient sustainable house. But it is also one of the most important as insulation can be the most cost effective way of making the biggest difference to your energy consumption (and therefore your bills).


As far as I can tell there is a type of insulation for all the different surfaces of your house. So roof / loft insulation, wall insulation, and floor insulation. Each type of insulation has different products available depending on your house and your requirements.

Roof Insulation
This comes in different types, but the most common and easiest to install (you can do it yourself) is blanket loft insulation that comes in big rolls. The important thing is to make sure it’s 270mm thick. It can be placed in between joists and then another layer can be placed on top.

Otherwise if you’ve got a funny shape loft with hard to access areas you can get loose fill loft insulation (again you can do it yourself). This is loose material that you spread out. It’s recommended to use 200 litres per square metre to a depth of 200mm (20cm).

Or you can get blown fibre loft insulation, which is similar, but needs to be professionally installed.

Finally there is sheet loft insulation, which is for the sloping sides of roofs and can be placed between the roof rafters and then covered in plasterboard. I think this is especially good if you are converting the loft into an extra room and are concerned about the loft losing heat and not just keeping it trapped in the rest of the house.

Wall Insulation
The kind of wall insulation you get depends on the kind of walls you have. Newer houses tend to have cavity walls, so the wall is made of two layers of bricks with a gap or ‘cavity’ in between. In this case you can get cavity wall insulation which is cheap and effective. They drill a hole into the cavity and blow the insulation in then fill up the hole afterwards.

If you have an older house then they might have solid walls (they were built like this up until the 1930s). In which case you are unlucky, as there are two types of insulation available to you but they are both far more expensive and labour intensive to install. You can get internal or external wall insulation. The external insulation is insulating cladding that can change the look of your house on the outside, but can be more effective than internal insulation which can leave gaps where internal walls meet the outer walls. The internal insulation is insulated dry lining which would need to be applied internally to the outer walls.

Basically if you have solid walls you should hope you have a terraced house as it cuts the number of walls to worry about by half (as long as you don’t mind sharing heat with your neighbours).
Other wall types like timber frames can effectively be treated as solid walls.

Floor Insulation
Floors either tend to be concrete or raised timber flooring. For concrete you can lay a damp-proof membrane, then rigid insulation on top, then cover with chipboard plus your desired floor covering. For raised timber flooring you can lay mineral insulation in between the joists in much the same way as you would with blanket loft insulation (mentioned above).

Finally for both types of flooring you can buy some sealant to fill in any gaps between the floor and the skirting board where heat may be escaping.

If your house is over two floors you don’t need to insulate the floor of the upper level, as long as the space below is heated (i.e. a living room). If the space below is not heated (like a garage) then it is worth putting in insulation in the floor of the room above.

That about covers it for insulation! Or at least it’s as much as I can stomach researching it until we have a house and know what kind we’ll need.

And on that note, we have had an offer accepted on a house! Things are still in the earliest stages, but watch this space. Relevant to this post, I think the house has solid walls, so insulating them will be expensive… Also floor insulation has been recommended, as you can see on the EPC snippet below.


My next blog post is likely to be on boilers. Like insulation this was not a subject I was particularly interested in until recently when ours stopped working and I had to have freezing cold showers for a couple of days…

NB: the girlfriend is not fully satisfied with this post as it doesn’t cover the environmental impact of the different insulating materials, or air flow and insulation / double glazing with regards to damp proofing. But never fear, I will broach these topics when I revisit insulation once we have our futurefitting house (oh joy).

Monday, 28 October 2013

(Solar) efficiency isn’t everything?


To be a truly sustainable, energy independent, energy efficient house I need some way to generate my own electricity. At the moment I can only see two viable options (although I’m open to suggestions!), photovoltaic (PV) solar panels and/or a micro wind turbine.

I was leaning toward trying to do both, but my spirirts were dampened slightly when I learnt how poorly the turbine at 3 acorns had been performing.

So despite the fact that the UK has been on ‘amber alert’ this weekend due to the ‘near gale force’ winds of the storm called St Jude, I think I’m going to have to put my trust in solar panels for the majority of my electricity generation.

I’ve been looking in to solar panels quite a lot recently, and there’s a lot of information out there regarding thin-film solar, mono-crystalline and poly-crystalline, etc.

It seems the important figure to pay attention to is solar module (panel) efficiency (different to the solar cell efficiency, which is a bit higher). The efficiency is how much of the sun’s energy gets converted in to electricity.

At the time of writing this, the most efficient solar panel is SunPower’s X-Series that is 21.5% efficient. If you’ve only just started reading up on solar panels, this seems like a fairly low number, but the thing to bear in mind is that theoretically the most efficient solar panel we can ever produce will only achieve 44% efficiency (as only a certain range of light within the spectrum is used in PV).

Of course you’ll see news stories of record breaking solar cells of 44.7% efficiency, but these are CPV, or Concentrated Photovoltaic cells that use a concentrator to effectively shine more than 1 sun’s worth of light on to the panels. So it’s not quite the same.

Sounds good right? Sign me up, I’ll take some solar panels and a concentrator please. But unfortunately they aren’t available for residential use, and the cost is prohibitive anyway.

But it’s not important. 21.5% is more than good enough for most people’s uses. Even 15% is good enough to make a real difference. And people are very good at pointing out that you shouldn’t be an efficiency snob.

I don’t think I’m an efficiency snob, but what does concern me is a slightly different issue. It seems like advances in PV technology are happening every week. And the price of solar panels is decreasing all the time. I worry that I’ll get some solar panels and then 6 months later there will be residential panels available for half the price that are an extra 10% more efficient.

Just in the last 2 weeks I’ve seen the following stories which always make me think in a few months to a year solar panel efficiency is just going to leap forward massively:

A quarter more efficient?

A potential breakthrough in efficiency? (and good news for LED lighting)

And a possible 80% efficiency?!

Of course this talk of efficiency may be irrelevant to me when the time comes and we've actually bought our house. You also need to pay attention to positioning. A south facing roof is ideal (south-west and south-east are fine too). You can put them on roofs facing other directions too, but you lose efficiency (about 15-20% for west or east. I think it’s far worse for north).

And then there’s the angle of your roof too. A 35 degree angle is ideal in London, but the optimum angle changes depending on where you are in the world (or even just the UK).

So I’m not an efficiency snob, I’m really not. But depending on what house we end up with, I might end up having quite an unsuitable roof to place my panels on, so every percentage of efficiency may count!

Tuesday, 15 October 2013

Lessons in LED lighting



I’ve been trying to write this post for a few weeks now but work has been so busy.

I thought a post about LED lighting would be a good way to ease in to looking at energy efficiency. It’s one of the cheapest and quickest ways to make a difference in your energy usage. However if you don’t know anything about lightbulbs other than how to change one, it can be slightly confusing at first.

So what prompted me to look in to lighting was a combination of two events. 1: my girlfriend Anne bought a new LED bulb for her bedside lamp from Tesco, and 2: I saw this buyers guide on twitter.

I knew there were different types of light bulb and that LEDs are the new efficiency kings, but beyond that my knowledge was pretty basic. Also I could never remember what CFL stood for or what it looked like. So after looking around I made my own quick guide to remind me:



Really the important thing to note is that the more efficient a bulb is, the less electricity it will use (in Watts) to produce the same amount of light (measured in Lumens).

So for instance, the LED mini globe Anne bought is 4W and 250lm. It says on the box that the equivalent conventional bulb is 25W. I’m not sure what ‘conventional bulb’ means. Whether it’s incandescent, or CFL (which are now pretty common that I’d almost call them conventional). But anyway, that’s potentially a change from 25W to 4W (I’m not sure what kind of bulb she replaced). If you were to do this with every bulb in your house that’s quite a saving. You could cut the electricity use in your house (on lighting) to less than a fifth of what you are using currently (although this is likely a big exaggeration if you are already using CFL bulbs).

The other benefits of LED lighting is the bulbs last for a very long time (25 years if used for an average of 2.7 hours per day, the Tesco packet says). Also LED lights produce hardly any heat as a by product of creating light, so they don’t get hot to the touch. And they don’t have a ‘warm up’ period like CFL bulbs, where you have to wait for them to reach their full brightness once you turn them on.

The downside? They are quite expensive. Buying a lot of LED bulbs is not cheap. But you can easily earn your money back in the savings on your energy bill over the years. Also as LED light become more ubiquitous the price will come down (If they’re selling them in Tesco that’s a good sign!).

So having been totally sold on the use of LED lights I’ve decided I’m going to replace every bulb in our new house as soon as we move in. I was so enthusiastic that I pestered Ecotopia on their range of LED lighting (among other things…). As previously mentioned I am slightly obsessed with Ecotricity, and as I already use Ecotopia I was keen to get them to stock the bulbs I was anticipating needing.



They will be getting some in stock, but in the meantime I found a good range on Nigel's Eco Store.

The other thing to take in to account though is that LED light can come in different ‘shades’ of white. The names vary depending on what website you’re looking on, but you can choose from ‘warm white’ ‘pure white’ or ‘cool white’. Which basically means a orange tinge, white, or a blue tinge. This depends on the Kelvin number. I won’t go into this in further detail though, more can be found here.

Also I read that the Wattage needed for a room is the square footage of a room multiplied by 1.5. So for a room 10 foot by 10 foot (100 feet) you would need 150W of lighting. Again I assume this is for incandescent bulbs. So using LED lighting you need the equivalent, which is about 30W.

I don’t think I’m actually going to worry about the Kelvin of my light, or the Wattage needed yet though until there are actually some real life rooms to apply my newfound knowledge to.

Although while reading up on bulbs I did come across this kickstarter, the Nanolight!

It had already been funded by the time I’d seen it, otherwise I probably would have backed it to get myself a Nanolight. I can see they’ve rebranded now to nanoleaf so maybe I’ll revisit their site when the time comes.

And finally. If anyone is looking to switch energy suppliers to Ecotricity (which I can highly recommend) if you quote this referral code ( RAFE-4WKE5 ) when making the switch, we will both receive a £50 voucher for Ecotopia. So I can use it to buy my LED light bulbs once they get their new stock, and so can you! (or you can spend it on toilet paper and dishwasher tablets)

Until next time.

Friday, 20 September 2013

Carbon negative house. Someone’s beaten me to it!

So this weekend is Open House in London. It’s where places sign up to be open to the public and people can go and look around buildings for free.

The one that caught my eye is 3 Acorns which is a Victorian house owned by Donnachadh McCarthy, an eco-auditor (amongst other things). He converted his 1840’s Victorian terrace home into a retro-eco home, just like I want to do!

Unfortunately I am busy this weekend, so probably won’t be able to go visit (although I might try to regardless), but I have been reading his website with great interest.

The first thing that came to mind is I was dismayed that his wind turbine was not producing much electricity at all! I may need to rethink my ideas for a micro-turbine. However his one was installed in November 2005. I am hoping that in 2014 when I am ready to start thinking about turbines that Ecotricity’s Urbine is ready for market. My hope is that it will be more efficient (due to being vertical axis) to make it a viable option (although I guess depending on whether the area the house is situated gets enough wind is a bigger consideration). Also I don’t know what the garden situation would be like, but I’d prefer a free standing turbine as they are supposed to be more efficient (but more expensive). So that might eliminate the problem the 3 acorns house is experiencing with vibrations.

Then the second thought was, I don’t think that this is a good model for a sustainable house. Obviously Donnachadh knows what he is talking about and has created a house that has achieved exactly what I want to do, but… I don’t like the idea of a wood burner.

Yes you can argue that it’s carbon neutral as the carbon produced from burning the wood is offset by the carbon dioxide removed from the atmosphere as the tree grew. But this is not what I take issue with.

I want my house to be energy independent. His house used 48 wheelie bins of wood in a year. It is reliant on there being a supply of wood. Obviously this isn’t going to be a problem for one household, but if you were to scale this up and asking every house in the country to become carbon neutral, where would you get enough wood?

Also a common complaint of non-environmentalists is that we all want society to regress so we’re all back living in caves. These people are of course idiots, but I do think that we have the technological advancements that allow us to have a zero carbon house without having to resort to huddling round a wood fire to keep warm. I think people are more willing to make a switch to renewables / low carbon solutions if they are easy and familiar and seem like an 'upgrade'.

If you are producing enough electricity to feed back in to the grid, why not use that electricity to heat the house? Of course it might not be viable, or it may be more efficient to do things this way. I guess the only way to find out would be to visit the house on Open House weekend!

Regardless, it's provided me with a lot of inspiration, hopefully I'll be able to surpass 3 Acorns.