4 steps to solar panels – a quick test to see if PVs could work on your roof

Over the last few weeks, I have talked to quite a few people about whether panels for electricity from solar ( photovoltaic panels (PV) ) are plausible for their roof. A lot of this is due to the government consulting on cutting support for PVs from January 1st (by up to 87%), meaning the financial payback on installing panels would typically increase from ~10 to 27 years. I’ve blogged before about when we when through the steps of getting our install together (to PV or not to PV), but I thought I would throw together a more general simple step-by-step…

If you live in a flat, the roof is one you do not solely own, or the install is on the larger side, some further steps are needed ( e.g. structural survey, certificate of easement…) however the general steps below are effectively the same.

      1. Work out a few details about your roof area and angle.

You will need to know roof area, roof angle, what angle it faces, how much shading it has, and whether the building has an energy performance above the minimal criteria (an EPC of D or above).

You can calculate the approximate area from eye or just use satellite photos. I tend to use Google maps through an app on a website like comparemysolar. Using this app you just place pins on the outline of the roof to get an approximate area. Google maps also gives you an compass orientation. As for angle, I would say it should be possible to get a estimate just from looking at the roof and comparing against a few examples. Then check for shading (e.g. chimney pots, neighbours roofs, trees…) and estimate what % of day you think the roof is shaded (another approach would just to check the roof at several times of day, but bearing mind this will change a lot by season). To check an the energy performance of the house according to its EPC certificate, and you don’t know it off hand, you can quickly check it on this website. If you do decide to get quotes, then all these estimates will be refined then anyway.

(e.g.  20 square meters, 30 degrees, south facing, no shading, EPC=D,  and in York)

      2. Estimate the rating of the PV install

There are lots of different panels of differing shapes, sizes, capacity and performance around. Choosing panels for the install may be easiest once you have quotes. I would recommend two sets of calculations, one for a lower capacity (e.g. ~100 W/sq m & cheaper) set of panels and one for higher capacity set of panels (~200 W/ sq m) . To get the peak output ( rating ) of the install just multiply the panel capacity by the area.

(e.g.  20 square metres * 200 W/square metres =  4000 W)

      3. Use some apps to estimate the output and payback of the PV install

We can now just plug the numbers from steps 1 & 2 to one of many online apps that use past solar data to predict how the panels would perform.  There are lots of apps to check whether PV is worthwhile and they give give a variety of different information from just the basic payback, to yearly/monthly break downs of energy production, and ones with lots of technical gory detail. I would personally recommend getting a broad overview from the Energy Saving Trust (EST solar calculator) and the Centre for Alternative Technology (CAT solar calculator, Caution: the monetary values were out of date when I last checked so just use for solar). If you are interested in more detail then the Joint Research Centre (JRC solar calculator) provides a lot more technical background.

The payback is made up of payments for generated clean renewable every (feed-in-tariffs or FITs), electricity savings (from use of electricity on site), and export tariffs (price paid per unit exported to the gird for someone else to use). The is more detail on this here and this will be broken down by the apps also. I understand that Installs for a typical residential install are generally between £4-6.5k at present.

(e.g. estimated to generate ~3300 kWh/year and have a payback of 9 years)

     4. Get a few quotes

There is a great list of recommended installers (need to be MCS certified) and a list of good questions to ask on the YouGen site. I also used the quote service from EcoExperts who quickly got us 3 quotes for comparison. The industry has taken a big shock from the recent government proposals to cut the fit in tariff and a lot of people may being trying to get installs before the expected changes to the tariff so it could be quite busy at the moment.

Once you have your quotes you can choose obviously between suppliers/installers, but also the capacity/spec of your install…. and whether you want to go ahead with it. The installs typically take a day for a 4kW domestic install and then the install will need to be registered via the installer through the government’s micro generation scheme (MCS), which installers tend to help with or just do for you.

Our installation was done whilst we were away on holiday; it was done quickly and without disruption.

(e.g.  Ecoexpert say from £3950 for a 4kW install. – Ours cost a little over £6k, but was rather technical and high spec for two years ago)

Links

Mid-Terrace to Mid-Terrific!

Recently we were asked to be part of the York Green open homes! This has caused me to reflect a little on our initial goals and how we have fared. As we spoke about in our first blog/“about” section, we are extremely frustrated by the how inefficient the homes we have lived in are and what is classed as affordable housing these days.

Essentially our goals were to make a home nicer to live in, making it more energy efficient and more sustainable at the same time. Quantitatively, we aimed to do this via spending ~10% of the value of the house on energy saving and producing measures that would allow us to meet the “A” grade EPC standard. As we’re doing Green open homes, i’m going to try and briefly highlight the rough interim energy and finical costs of the project.

As an attempt to preempt what i expect will be the biggest FAQ, i’m going to try and outline the money side on the project. To be 100% clear this is rough estimate. Although we can talk about the money and carbon case generally, honing down more figures is challenging as we don’t really have a good handle on the house’s prior performance. This is because we started doing our retrofit slowly from day one, we don’t have any data before we moved in, and then had an some alteration re-done by an insuracne company. This is a broad (very) rough attempt at approximating what we’ve achieved so far. In a year or so i will have enough data to do this more robust, but is i suspect the money side of things is a big questions for people so here it goes…

The (estimated) overview Financial Case for our EcoRetrofit
It make me a little uncomfortable giving away such exact details… but as everyone asks because it is a litmus test for the project’s success and since we live in the age of Zoopla it’s not like its difficult to find out anyway.
So we bought the terrace for £121k, this was the bottom of the market for houses close to central York. There were some issues, like a leaky roof and a damp problem, which is relatively common for a house of this age and type. Following our eco-renovation, the house was recently re-evaluated to be worth £145k, an increase of £24k (20%). This far outweighs the cost of all of the energy improvements (~£12k). The attribution of the increase in value is challenging as the housing market has increased the price as as-well as the renovation, but as zoopla tells me this is 10% it is fair to say the eco-renovation played a part although the percent due to the “eco” and “renovation” part of the eco-renovation is unknown. However, it is important to caveat this with the obvious fact that until we sell the house (which we currently have no intent to do!), we cannot know for sure that this increase is real.

The real savings that will payback the cost of doing all the work are seen through the bills (assumed at £26/month, 50% 
usage at house). For the first year after installing the panels our bills total of ~£37/month for electricity and gas, which is paid for in excess by income from the PVs (~£60/month, albeit offset as one payment is quarterly and the other is monthly). These bills are low, for a house our type i would estimated expected bills to be £700-900. I predict these to increase after next winter as we essentially had just electric heaters this winter due some issues with the boiler, although with that said the electric heaters are more expensive per kWh, but regardless it is low.Getting the money to do these kind of work and the upfront nature of the costs often deters people. We paid for the work using a mixture loans, savings and income. With current interest rates low borrow money if someone is willing to lend it currently. So this shifts paying back for the cosy/cheap to run house to over the payback period. The government “Green Deal” scheme could be an option for many and it has been extensively discussed on the internet, including on MoneySavingExpert with some great worked examplesenergy saving trust, and YouGen. The point needs to be made though that a lot of improvements that have a large impact are cheap like managing drafts or made very simply subsidised/free by the government such as installing loft insulation.

Best & worst of our larger choices

 

Best of our larger choices: Photovoltaic Solar Panels
The solar panels (PVs) are out performing our expectations. Not only in energy production (130% of consumption in the first year), but also in the impact on our bills. The payback is currently less than 7 years and could be lower if the we use more at the house rather than sending it to grid. This would be easy if we had hot water tank, as you can just route the excess electricity to heat the water that would have been heating by gas or electricity for baths etc later in the day. For us it is more likely that a battery storage system like Ecotricity’s Black BoxTesla’s PowerWall or Enphase’s energy storage system as our consumption is majority through electricity.

 

With a guaranteed lifetime of 25 years, and even if the panels do degrade by ~25% in output terms over this period (maxim allowed by warrantee), its hard to imagine them packing up straight after this. I’m intrigued to see how they fare over longer timescales, but just taking the next 20 years that they receive government subsidy they represent a huge saving in carbon dioxide emission

 

On the carbon side, they have already paid off their carbon from production. We’ve recently done a lifecycle assessment on the panels, and will post this shortly. Without giving too much away it looks good, and depends heavily on the choices of how you treat the export of electricity to the grid from he PV panels.

 

 

Worst of larger choices:  Upgraded Boiler (D=>A)
We weren’t naive about this, but this was a compromise we had to make. Although we were told, and i know others often are, a new boiler is the best action. for low users like ourselcves the enormous cost of a new boilder (£2.3k, installed), just doesn’t add up. And thats not even considering the embodied energy cost of new boiler. The boiler broke whilst i was working out of the country and we had previously refused to upgrade against recommendations, along through the tick box exercise of EPC certificate  this and the TRVs have pushed us firmly into the A category.
 

Financially the payback can only come from savings. Considering our gas bill is currently ~£10 a month (although, i expect this to rise to £15 a month),  this is basically impossible. This is low as our shower is an electric one, we may not keep our house as hot as some do, and hopefully some credit to all of our eco-renovation efforts! I estimate the payback period for the boiler to be greater than the current UK life expectancy. The last boiler was only 5 years old (Chaffoteaux et Maury, Minima Mk2 30 FF), and although we’ve got for a more reliable model with 10 years warrant (Worcester, Greenstar 28) i won’t be holding my breath.

From an environmental angle, even though we are on biogas tariff, we pull from the main grid and this essentially still fossil fuel. On this count an air source heat pump would actually have been better, but for cost reasons and due to working out of the country at the time we needed to replace the boiler it wasn’t an option. I remain skeptical this technology and would prefer ground/water source for energetic reasons if we had the space, although I have friends who are convinced.

Any lingering thoughts, Would you do this action again to another house?

Yes. On the financial side alone it was definitely worth our while over a 6.2 year timescale (with less than 4.5 years remaining). Over long the financial case gets stronger. If we include other qualitative improvements like how draughty/cosy the place is then the yes is even more resounding. The smaller and cheaper changes will have contributed a lot to this. I will be able to do a better analysis when i have more data, from which the real savings in energy consumption and costs can be calculated.

 
I’ve just tried to outline the broad money side of our project with a few examples. But i can’t personally do this without pointing out that “Externalities” (e.g. costs of air quality) of conventional heating/Electricity options are thought to be huge. Although we pay for these via our taxes etc, it is important to bare that in mind ( a back of the envelope calculation gives air-quality costs as £250-850 per person per year, which is from £1654 bn in costs and ~64.1m people ). Trying to look at more of the picture (but by no means all!) rather changes the way we can see the economics of energy pricing.
 
Its is challeneging to express quite what a improvement it is to live in a warm cosy house without huge cost ( energetic or financial ). It will be possible to quantify this in the near future, and there are some great examples of projects that have managed this ( like a carbon coop project with @zapaman in Manchester ). Here’s to cosy, more sustainable and cheaper living!

 Links
Disclaimer: I am not a financial advisor and do not work in finance. This article links to research/information I’ve found and expresses my own opinions and experiences. I hope it is useful to you but in no way am I offering financial advice or recommending a particular course of action. If you’re considering any investment you should seek information from a wide range of sources and speak to an independent financial advisor before making any decision. I’ve tried to be as accurate as I can, and when prices have been quoted those were available openly on the date of publication. If you see any errors/broken links/have any comments please just drop me an email or comment.

“Roof-less” Micro-investing in Renewables – For when you can’t have panels, a wind turbine or hydro etc yourself…

This article is a little intro into buying into renewable projects from ~£5 upwards. Its something that I’ve been involved in for a while now and feel it has enormous potential, with billions per year being raised through crowdfunding. I often meet people who are interested in crowdfunding, but rarely people who know about the application to renewables.

Why micro/smaller renewables?

Renewables now provide 17% of UK electricity consumption (2013 data), with the majority of this from coming from the big six. This control within the market doesn’t exactly work for the consumer (nicely overviewed by this FT article) and it has led to a large amount of press coverage. This is continually brought up in government time and calls have been made to make the “big six” the big 60.000 instead ( e.g. from the Energy Minster Greg baker) . What if we as individuals in the population had a degree of ownership of this new energy generation? (e.g. fig. 1. >50% of share installed capacity in Germany in 2012) Could we direct more money into our communities? Would we feel more involved in tackling climate change? Could we increase the construction of renewables?

Performance of renewables and our policy driven goals mean that as well as the environmental motivations, from a business or investment standpoint renewables are great idea (A Government Minster even recently said “Solar panels [are] better than a pension“). This is further demonstrated by the press coverage and strength of the reverse argument: divestment. Here i’m going to run through the general money case and how to get involved and won’t cover the social and environmental side.

German energy transition is a democratic movement (Read more at 2.I – Energy by the people)
fig. 1 – German energy transition is a democratic movement (Read more at 2.I – Energy by the people) – Figure and Caption reproduced from energytransition.de

What if you don’t have space for PVs etc?

Due to renting, living in flats, urban locations or unsuitable roofs not all of us can have renewables on our own roofs or in our back gardens. However being part of the process of decarbonising our energy is something more people feel motivated to do. There are lots of worthwhile changes we can make to energy use in our houses, and this blog is charting our exploration into those, but importantly the choices and influence over energy delivered to our houses is also becoming within  grasp.

We can choose suppliers for our homes that aspire to reduced carbon content/100% renewables ( e.g. Cooperative Energy/Good Energy) or actively work to build renewable infrastructure (e.g. Ecotricity). Regardless of your position on energy generation the contribution of energy we use in our homes is ~30% of national electricity consumption (fig. 2) and energy generation is clearly going to be close to home for a lot of us in the future. Our little renovation in Yorkshire for instance is close to proposed/operating wind turbines (e.g. Private: Knabs Ridge; community: Blackshaw HeadGrimethorpe and Cudworth, Norton) and fracking exploration (Kirby Misperton); so getting actively involved becomes a much more present and proximate issue.

Ofgem: Electricity Generation: facts and figures - http://tinyurl.com/qzqp44v
Fig. 2 Ofgem: Electricity Generation: facts and figures – http://tinyurl.com/qzqp44v

Investment… don’t you need lots of money for that? 

Micro investment in renewables is where developers of energy projects raise the capital by lots of smaller “shares” to interested members of the public, rather than seeking larger amounts from fewer investors or banks. Billions of pounds have now been raised through crowdfunding by sites like Kickstarter, and it is a now an established investment model globally for renewables (fig. 3). Shares typically start from £5 upwards, and both community and private projects have gotten off the ground.  These projects generally have projected returns/ROIs of 5-7% or above, which is much higher than usual high-street cash rates (e.g. ISAs/Bonds etc). Typical recent examples are 6.65% IRR ( PV – SunShare) or 8.4% – 9.3% IRR (Wind – REG High down). The way they operate tends to be through raising initial capital through share or loans to setup the renewables and then the income is generated through selling the electricity and government payments for generating the electricity (FITs) pay the ongoing costs, community contributions and returns to investors. The play-off for the higher rates is due the decreased access to the money for the duration of the investment, longer terms (normally ~3-20 years), the return often is un-guaranteed, the capital is at risk and there is a lack of transferability (shares tend to be exchanged via mediated offers, dependant on buyers). Each project is different, and the terms will alter so weighing up of pros and cons has to be done on a project by project basis.

Global renewable crowdfunding
fig. 3 . Global renewable crowdfunding credit: @SolarPlaza via @TrillionFund 

Interesting, how established is it and is it for me?

Being part of renewables is now a choice open to all, which is starting to revolutionise the energy market and proving a game changer for schools, communities and companies. Although direct ownership arguably leads to the greatest returns if plausible (as I discussed a little when we installed our PVs), utility scale renewables are cheaper per kWh, and offer greater capacity and value to the consumer. Below are some related links including the main UK platforms and serval examples of projects being funded or just getting up running, and long term established projects.

Here are further some refs/links:

Disclaimer: I am not a financial advisor and do not work in finance. This article links to research/information I’ve found and expresses my own opinions and experiences.I hope it is useful to you but in no way am I offering financial advice or recommending a particular course of action. If you’re considering any investment you should seek information from a wide range of sources and speak to an independent financial advisor before making any decision. I’ve tried to be as accurate as I can, and when prices have been quoted those were available openly on the date of publication. If you see any errors/broken links/have any comments please just drop me an email or comment.