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Wednesday, 9 April 2014

Renewable Heat Incentive (RHI) Key Points

Today sees the eventual launch of the domestic RHI. So here are a few pointers for you so that you don't have to pour over the finer detail to see if it is right for you - although we do suggest that if you do decide that it is a good deal for your home that you do look at the Government website and associated docs

What is the RHI?
This is a financial support scheme for renewable heat, targeted at, but not limited to, off gas grid households.

Who is eligible?
The scheme will cover single domestic dwellings and will be open to owner-occupiers, private landlords, Registered Providers of Social Housing, third party owners of heating systems and self-builders.

What sorts of technology will it support?
The scheme will support air source heat pumps (ASHP), biomass systems, ground source heat pumps (GSHP) and solar thermal technologies.

If I have one of these technologies already can I claim the RHI?
The scheme will be open to anyone in these groups who installed an eligible technology since 15th July 2009, provided they meet the criteria. See Gov website for more info as this is a bit more involved.

How much will they pay?
The system pays you for each kWh of heat that you use. This varies between technologies:
ASHP - 7.3p per kWh
Biomass Boilers - 12.2p per kWh
GSHP - 18.8p per kWh
Solar Thermal - 19.2p per kWh

But, hang on ASHP and GSHP use non-renewable electricity to run, are the Gov going to subsidise this output?
No. There is a calculation for those technologies so that the non-renewable elements are removed before the RHI is calculated.

What about wood, should that come from sustainable sources as well?
The Government is developing an Approved Biomass Supplier list and all biomass will need to be sourced from this (and evidence is required to be held) in the near future.

Can I have two RHI's given that solar thermal will only heat the water?
Yes, you can have one RHI for space heating and another for the solar thermal.

How long will it last?
Payments will be for 7 years and paid quarterly

Will the payments change?
Once you have your rate agreed it will be linked to the RPI, so might go up or down in line with that.

Will the RHI rates drop like the Feed In Tariff?
There are a number of Degression Triggers that the Government has set and this depends on uptake, so once a fixed amount has been reached then the support will drop by 10%. There is also a super trigger, so if the demand is so high that the Government is spending its allotted £ too quickly then a 20% decrease might occur.
There will also be an annual review and they may well change rates in line with projected uptake etc.

How do they measure usage?
The renewable heat generated will be estimated in most cases for payment purposes. For biomass and heat pumps, it will be based on an estimated figure of heat demand from an Energy Performance Certificate. For heat pumps, this will be combined with an estimate of the heat pump’s efficiency to determine the renewable proportion of the heat. For solar thermal systems, the payments will be based on the estimate of system performance completed as part of an MCS installation. Those applying for a space heating system who have a back up heating system, such as an oil boiler, or people applying for a second home, will need to install metering equipment on which the RHI payments can be based.

That doesn't sound very accurate is there a better way of doing this?
There will be an extra incentive for applicants who install metering and monitoring service packages, of £230 per year for heat pumps and £200 per year for biomass boilers. However, it might be that the EPC over estimate usage and so you might be better off with taking those figures.

Do I need to have improved the energy efficiency of the house before applying?
Renewable heating systems work more efficiently in a well-insulated home. Therefore, it is a requirement that all applicants complete a Green Deal Assessment before applying and to ensure that they have met minimum energy efficiency requirements of loft (250mm) and cavity insulation (filled cavities).

Is there a quality scheme that backs it up?
All installations must be certified under the Microgeneration Certification Scheme and meet relevant required standards for each technology, including limits on harmful emissions for biomass systems.

How do I apply?
The recommended way is through the Ofgem RHI website

Wind Turbines - Barking up the wrong pylon?

Large turbine up in Tredegar - split the residents. 
This is a relatively new 45m high turbine in an industrial estate up in the Welsh valleys. It has been interesting reading the Tredegar Forum so see the comments that people have been making. There is a split along the lines of:

Why weren't we told about it?
It's too big
It can be seen from across the town

More attractive than the pylons that are also in the area
Better to be in the industrial estate than elsewhere

So, it appears that people would be happier with wind turbines if:
1. Smaller turbines are installed
2. They are involved in the process
3. Turbines are in areas that are already blighted by man's industrial hand
4. Turbines didn't always mean a lot of associated pylons

So, one answer might be to change our planning policy so that in Wales (and the rest of the UK) we can encourage organisations to install smaller turbines in industrial areas. Ideally these turbines would be community owned or at least have a community benefit attached to it so that people felt involved in the process. By having smaller turbines in urban areas it would mean that all the power could be used locally rather than having to install lots of 'ugly' pylons. Turbines on land that is already industrialised should mean less pressure on the countryside or seascapes to house huge wind farms. This in turn reduces NIMBYism in the more sensitive rural areas, especially with regard to pylons. With quicker planning, this would help us to reduce our carbon footprint even faster.

An an example here is a picture of an industrial area in Amsterdam

 Click for full size version
Click on the picture to link to a larger scale picture that shows the turbines more clearly

Tuesday, 8 April 2014

Bio Solar House - THE Passiv Haus alternative?

Example 6
An example of a Bio Solar Haus
In the UK we have a couple of recognised building standards: Code for Sustainable Homes and Passive House (Passiv Haus). CSH is based on SAP and a range of other factors, but this will soon be phased out and replaced by Building Regulations. This will then focus on energy usage. Passive Houses use PHPP to calculate how the building will perform, and again it is focused on energy use. PHPP is much more accurate than SAP, but there is an element missing in both because of the focus on energy use. That is what it is like to live in it.

In Germany an engineer called Klaus Becher decided that he wanted to build a low energy house that did not rely on mechanics and electronics to work efficiently. As he puts it:

'nature offers the simplest and cheapest solution to all problems. I wanted to build myself a retirement home, that would keep me healthy, required little technology, used little energy, was easy to maintain, protected the environment, liberated me from constantly rising running costs, gave me my desired space and was affordable.'

So using his engineering background he set about designing and building a house. So what he has come up with is an ingenious solution of a House in a House. This means that the structure uses nature to drive the heating and venting of the house by the means of an internal 'Winter Garden' that collects solar gain, which in turn expands the air in it and uses this pressure differential to push the warmed air through the building. Summer cooling is provided by using air passed through ducts in the ground. Heating is generated by solar collection as well and then disseminated by a wall heating system. If additional heating is required (on those cold dull days, then a small biomass boiler is used to drive the system).

To top the environmental credentials the designs are based on using wood as the main source of material. So the whole house becomes a carbon sink as well.

A Holzhaus (Wood House) from Bio Solar Haus
In the UK, these houses only come in kit form, but you can have almost any shape or configuration, depending on your design needs and sensitivities. The main external house is the main frame of the building and the internal house is then designed to be a flexible space, so the house can be altered to your changing needs. Marvellous.

So if you are looking to build your own home it is worth remembering that there is an alternative to Passive House that won't have you fretting about MVHR's, automatic shades etc.

More info can be found at for the English site and for the German. Holzhaus info in German can be found at

Thursday, 3 April 2014

Which is the best light bulb?

Incandescent, CFL or LED?

Choosing a bulb would appear to be a straight forward choice. Incandescent bulbs are slowly being withdrawn as they are better at making heat than light! However, we are very used to the light that they give and the way that they do it. The change over from incandescent to better efficiency bulbs has been a focus of the energy saving movement, but it has hit upon a degree of resistance from the great British public. So what are the choices now that the market has matured a bit?

Incandescent and halogen bulbs are high energy users, but they do give a instant light that has a high CRI value. A what? CRI is Colour Rendering Index. So this tells us how much of the visible spectrum is given off by a bulb. CFL bulbs have poor CRI, hence the light that they produce makes colours appear different. LED bulbs give off a better CRI than CFL bulbs.

Another common complaint about energy saving bulbs is that they are duller than the incandescents and halogens. This can be true, if you don't get a powerful, or efficient enough one. We are used to looking at the wattage of the bulb and also believing what companies tell us are equivalents, whereas we should be looking at Lumen output. Lumens are a measure of the quantity of light. So if you want an equivalent to a 60w bulb you will need to match its light output which is around 600 Lumen. This means that you will need a modern CFL bulb of around 11w and a LED bulb of around 6w. But check the box as there is a wide variety of outputs for different types, shapes and colours of bulbs. Colours??

Well now, a whole different area. White light comes in a variety of colours! This is measured in K (Kelvin). Warm whites (incandescent and halogens produce warm white) is around 2700 to 3000K. LED and CFL bulbs are available at this colour temperature. But they produce more light at higher K, but this means that they produce a whiter / slightly bluer light and this is commonly called Cool White. Cool White is around 5000K. You can also get Daylight bulbs at around 6500K. The different light that these bulbs give off is very different and so make sure that you are getting the right Lumen with the Colour Temperature (K).

So what with size varying, the amount of time required to get to full brightness (CFL's have to warm up, whilst LED is instant), cost, length of time a bulb is on for (no point investing loads of money on a new bulb if it is only on once a week for a few minutes!), guarantee periods (these tend to come with LED bulbs), estimated lifespan (LED bulbs have the longest span, but CFL's also have a good lifetime), location of bulb (is it hard to get to? If so you might wish to go for the longest projected life), is it on a dimmer? etc etc.

Get the idea? There is a huge variety of factors that can influence what bulbs you might put where. So, it is worth thinking a little about the lights that would suit you best.

If you need instant light that will be on a lot - LED
If you need background light - CFL
If you need a high quality light - LED
If you only use the light ever now and again - keep what you have!

You get the idea.

Just be aware that there is a wide variety of choices and that not all bulbs are the same.

Check Lumen, not Watts.
Check Guarantee as well as Lifespan.
Check Colour Temperature to ensure who have the right type of light.
Check size to ensure that it will fit in your fittings (especially important for some halogen replacements). Check to ensure that your bulbs are compatible with your dimmer system (if you have one).

Wednesday, 2 April 2014

The BEST training out there

Introducing the BEST training programme for upskilling the existing construction workforce into more sustainable principles and practices! Just click on the picture to play the BEST introductory video (via YouTube)

For all the Welsh speakers out there, here is the Welsh version.