Are PV Switches Abusing the FIT Scheme?

A first for the solarblogger, and something I’d really like to see more of.  Here's a guest blog by Tom Seppings of Solaplug, a UK manufacturer of an innovative immersion heater replacement that converts a standard hot water cylinder into a solar cylinder.

This outspoken article echoes an earlier solarblogger post, and I'm expecting it to stimulate some discussion.  Please use the comment box at the bottom to join in.

the solarblogger

Are PV Switches Abusing the FIT Scheme?

The FIT scheme is a fantastic success, which has brought renewable electricity generation to hundreds of thousands of homes.  But any subsidy scheme has to be tweaked from time to time. 

In the past few months we have seen PV switches which dump surplus renewable electricity into hot water tanks as heat, cross over in to the mainstream market.  Are PV switches exploiting loop-holes in the FIT scheme for financial gain? Do they bring environmental benefits?  Are they fair to solar thermal?

Installing electricity generation at the micro level incurs disproportionate overhead and "hassle" costs.  In 2009 DECC considered, pragmatically and practically, that mass export metering was too complex and costly, and that 50% of electricity generated through the FIT scheme should be "deemed" as exported to the grid.

However 3 years after the FIT scheme was launched, this loop-hole is being exploited on a large scale.  Microgenerators of electricity are paid for exporting 50% generated, whether they export it or not.  Many, with the help of PV switches, are choosing to be paid for exporting electricity, and then retaining the power by degrading it as heat in their hot water cylinders.

We have a Feed In Tariff Scheme that does not require the generators to feed in!

Electricity is a very versatile and still highly subsidized form of energy, heat is less subsidized and a much less versatile form of energy.  Also electricity is a much more carbon intensive form of energy, in the UK on average 0.508 kg of CO₂ are emitted to produce each KWh of electricity. To produce 1KWh of heat by burning grid gas emits 0.187kg of CO₂.

So if a home owner with a PV installation and grid gas heating decides to dump his surplus PV power as heat to replace some of his gas heating, he is effectively increasing his CO₂ emissions, and reducing the carbon benefits of his PV.

Installing a PV switch may be within the FIT rules, but is this following the spirit of the scheme?

It could be said that PV switches abuse the FIT scheme environmentally and financially.

Over the past (nearly) 4 years with FITs for PV, and until yesterday no comparable subsidy for solar thermal, PV has far outsold solar thermal. To the extent that many people don't even realise that solar thermal exists.

Now with the help of a PV switch, a PV installation can generate hot water.

We effectively have 2 types of solar water heating, solar thermal and solar PV, and they cost similar amounts.

A 2KW PV system should generate 1700KWh/yr of electricity, and it could cost between £3000 and £4000.

A 4m² solar thermal system should produce a similar amount of heat, and cost about the same.

The main difference for the home owner, will be the subsidy rate. For PV 15.44p/KWh over 20 years, and 19.2p/KWh over 7 years for solar thermal.

Even after yesterday's announcement, the vastly different levels of subsidy amount to a chronic distortion of the solar water heating market.

Solar thermal still has some advantages. It takes up less roof space, and performance is less susceptible to shading. So there are many more homes in the UK suitable to solar thermal than PV.  Also, solar thermal has not yet enjoyed the "kick start" so successful with PV to enable costs to reduce, there will be opportunities for cost reduction from today's prices.

It is still possible to imagine a time 20 years from now, when energy will be much more expensive and subsidies for microgeneration are minimal or zero. And solar thermal outsells PV.

Tom Seppings, Solaplug Ltd

Wrong on Many Levels

The solarblogger is Concerned For You

While out and about near Cambridge, I passed a building site and snapped this photo. 

 

Discretion is my middle name

I guess I was planning to rant on my blog about one or all of the following (take your pick):

• The box-ticking mentality that results in house builders giving their customers a 0.5kWp solar photovoltaic system – something that no one would ever buy for their own home (see my earlier blog Specifying Solar for New Build Houses)

• How there’s really no excuse for these solar panels to be installed like an ugly roof-rack (see one of my most popular blog articles – The Best Looking Solar Panels You’ve Never Seen)

• Why the designers didn’t choose one of the many low-profile roof integrated solar options that would have been so very easy to do as a new roof was going on anyway.

It was only when I downloaded the photo and reviewed it on a larger screen, that I realised what I’d inadvertently caught.

Did you see that in the background?  If the guy working on the roof between the solar panels slips, they’re both coming down.

Can you see what it is yet?

I’m guessing what we’re looking at here is the result of having to install to a price. In new build, the panels are often fixed in place by the roofing contractor and you can’t complete the electrical installation until there’s mains power in the house (which normally means long after the scaffolding has gone). Repeat visits to site are costly, better to do it all in one trip than to make the electrical connections to the panels when the scaffold is up.  Must be really tempting to just nip up there on a ladder and get it done.

Is there a better way?  Well, one option is to roof-integrate the solar panels at the same time the roof covering is going on, pass the electrical connections from each panel through into the roof space and the whole system can be connected up from inside the building.

Perhaps you think I'm worrying unnecessarily for the welfare of my solar colleagues?  Is this 'elf and safety gone mad?  If the ladder was tied on, would that make it OK? Please post your thoughts in the comments box below...

Note Added: 22/07/2013

People have started to send me photos of their own - I have started an image set on Flickr here.  Please keep 'em coming!

SAP 2012 Gives Solar Heating a Boost

What the Government's new Calculation Means for Solar

Credit: Viridian Solar

Ahead of the announcement of the new Building Regulations later this summer, BRE has published the accompanying energy calculation, the Standard Assessment Procedure, or SAP.  

If you think this document is only relevant to the new build sector, you would be wrong. SAP is also the basis for Energy Performance Certificates (EPCs), and therefore is also highly influential in the refurbishment of existing homes, for example under the Green Deal. SAP Appendix H is also used by the Microgeneration Certification Scheme (MCS) for installers of solar heating to provide customers with an estimate of their likely energy savings. Finally, whichever of the proposed routes to calculate payments under the forthcoming incentive scheme for renewable heat, the domestic RHI, is chosen, SAP lies behind it somewhere.

This document is not for the faint-hearted, comprising a thick booklet of dense calculations and notes. Fortunately the solarblogger has done the heavy lifting, so you don't have to...

A detailed assessment has been published as a briefing document available from the Viridian Solar website, but here's a quick round up of the headlines:

►  New postcode-based irradiation data (PV&T)

The UK average irradiation remains the same, but the value varies depending on location with northern Scotland around 10% below the average and southern England around 10% above.  This feeds directly into the solar pv estimate, but results in a smaller +/- 5% change across the country for solar heating.

► Updated fuel carbon emissions factors (PV&T)

Carbon savings from solar electricity reduce by 2%, carbon emissions avoided by solar thermal replacing natural gas increase by 9%

► Addition of hot water use factor (T)

There is a 29% increase in hot water used from the hot water cylinder in the solar thermal calculation if no electric showers are present, and a reduction of 36% if only electric showers are present. This produces a 20% increase in solar heating energy in SAP Appendix H compared to the previous version

► Reduction in solar pump electricity consumption (T)

The 75kWh flat rate for the solar pump electricity consumption is reduced to 50kWh for mains powered solar pumps, based on evidence from EST solar thermal field trials submitted by EST and Solar Trade Association

► Addition of second order coefficient for thermal panel efficiency (T)

Creates a level playing field (for more information see my paper on this issue here)

So What Does it all Mean?

Photovoltaics

For solar PV, the main impact will be on new build housing.  Here the changes are relatively neutral, being a 2% drop in carbon savings on average due to the lower emissions factor for solar electricity. Of course, compared to the previous version of SAP, which used a single figure for irradiation for the entire country, some areas have increased significantly while others have fallen. (See map, below)

Credit: Viridian Solar

For retrofit PV the recent MCS PV installation Guide has already implemented a new energy calculation based on a different set of  irradiation data.  This produces slightly higher energy outputs than SAP 2012.  The discrepancy could be explained by the different uses of each calculation, with the MCS method taken to predict year one energy (with solar panel performance degradation taken into account later for any financial forecasts).  By contrast, SAP is more aimed at producing a whole life average estimate.

Solar Thermal

For solar heating, the calculation impacts both new build and retrofit, and in a really positive way. (See map, top of post)

In new build, carbon savings will increase significantly for almost all homes with solar heating.  The new adjustment factor for electric showers rightly produces a disincentive to install these alongside solar heating.  I reckon that overall the boost to solar heating carbon savings from all the changes is worth between 17% and 31% depending on where the house is.

In retrofit situations, the MCS installer will perform an energy calculation  for the customer using SAP Appendix H. The new version of SAP will an average of a 20% boost to the solar energy estimate, again differing depending on the location of the installation.  

Further changes are coming down to road to improve things even more in MCS, more on this soon....

A Chink of Light for the Solar Heating Industry?

What the new £600 Grant Really Means for Solar Heating in the UK

Are you a glass half-full
type of person?

The Department of Energy and Climate Change (DECC) announced today that grants given to households installing solar heating and other renewable heating technologies have been doubled in value.

The grant for solar heating under the Renewable Heat Premium Payment (RHPP) is increased from £300 to £600.  Householders will have to spend a bit of the extra money on a Green Deal assessment, at a cost of around £100.

The move follows lobbying from renewable heating trade associations and a twitter campaign initiated by the solarblogger. 

The #TweetforHeat campaign had the aim of attracting the attention of the Climate Change Minister, Greg Barker, to a blog article on this website – 'You Just Couldn’t Make This Up'.  The article points out the damage that successive delays to the domestic Renewable Heat Incentive (RHI) has been doing to the renewable heating industry and proposes an increase to the grants as an immediate measure to help the industry get back on the front foot.

While the grant increase will undoubtedly boost installation rates for solar heating and is fantastic news for the solar industry, the most important aspect of this might not be the grant itself but rather what it signifies.

A Shot in the Arm

You see a feature of the argument to increase the grant was that DECC had revealed in its own consultation on the domestic RHI its intention to pay the RHI net of grants already made.   

If DECC truly was serious about launching the domestic RHI next spring, then the extra money to increase the grant would cost government nothing extra. 

After promoting solar heating systems to householders based on the promise of a future RHI, many solar installers had lost faith that this scheme would ever see the light of day.

The increase in the grant and Green Deal tie in sends a strong signal to the industry that DECC really is serious about getting the domestic RHI going next spring.  Because solar heating systems installed today will be able to apply to join the RHI once it launches, solar installers should be able to get back to promoting solar heating to householders with a renewed confidence.

For its part, government needs to ensure that it gets the promised summer announcement of the scheme details right.  The announcement needs to be comprehensive, including not only the tariff levels, but also the qualification criteria and the method for deeming the energy upon which the tariff will be paid. 

Once this information is out, (and assuming a reasonable tariff rate for solar) DECC will have put everything in place for the solar heating industry to really show what it can do.

Winners and Losers, but Mostly Winners

Changes to the MCS Photovoltaic Energy Calculation

The solarblogger has been working on a briefing document about how the new MCS PV Guide has changed the landscape for solar photovoltaic installation companies in the UK.

I've reproduced the results of the analysis below, speaks for itself really.  For more details on how it was arrived at, read the briefing here.

Here's a thought.

If the EU Trade War with China adds 50% to the cost of PV modules (BBC News reports the average is 47%), and if the modules are around 40% of the total installed cost of a domestic system, then the cost increase to domestic customers will be about 20%.

The increase in the MCS energy estimate maintains the return on investment for customers....well, so long as they live in Kent.

Is the Solar Keymark Fit for Purpose?

The Solar Keymark is held up as the "gold standard" for solar thermal accreditation, but is it still up to snuff?

So what happens when it rains?
Image courtesy: Viridian Solar

 They say that Nature abhors a vacuum. National test laboratories on the other hand love the stuff, and they've been falling over each other to fill the vacuum left by the current embodiment of the Solar Keymark with highly profitable testing requirements and a hotchpotch of local standards.

Ireland, France and now the UK have introduced additional requirements for solar thermal installations, and guess what? They're all ever so slightly different.

Solar thermal panel manufacturers are tearing their hair out. How has this come to pass?

The Keymark is intended to ensure the performance and durability of solar thermal collectors. A random sample of solar panels from the factory is selected and subjected to a battery of tests at one of a small number of accredited test laboratories.  In addition, the quality systems in use at the factory are regularly audited.

The tests are designed to answer the question "are the solar panels you're making this week any good", and the audit answers the question "is what you're going to be making next week anything like what we just tested?"

The tests are based on the European standard EN 12-975 parts 1 and 2. Part 1 determines the thermal performance of the panel, while part 2 assesses the durability of the solar panel. A series of tests attempt to break the panel, for example:

·         Leaving it to bake in the sun, then pumping cold water through it

·         Leaving it to bake in the sun, then throwing cold water over it

·         Dropping a ball-bearing onto the glass

·         Spraying the panel with water and seeing if any goes inside it

·         Trying to break the glass by pushing and pulling on it

It really is a very good test of the solar panel.

Unfortunately, it only considers the solar panel in isolation.

In most real life situations, a solar panel is attached to the roof of a building. People can be fussy about their roofs.  Most seem to prefer that the water stays outside when it rains and that the roof doesn’t end up in the garden after a windy night.  Building Regulations cover these two points, to which they add the requirement that if your neighbour’s house is on fire, your roof shouldn't go up in smoke at the first lick of a flame.

In theory a solar installer must be able to demonstrated to building control that the solar panel they have installed does not impair the weather tightness of the roof, is proof against the wind loads it may face, and is installed the correct distance from the boundary for the fire rating of the panel.

How does the Keymark help the installer with this?  

It doesn't.

Enter MCS012 (UK), CSTBat (France) and Irish Agrement (Ireland), none recognising the other.  (Read my article about MCS012 here)

The Keymark is no longer meeting the needs of the industry for a single, Europe-wide test to ensure free movement of goods and services.  It rapidly needs to mandate the following additional tests:

1. A wind uplift test with a defined substructure to which the panel is attached. The substructure should be representative of a worst-case timber width, as the strength of fixings to timber is affected by the ratio of timber width to the screw diameter.  The tests should also take into account that timber is a natural material, which is normally done by repeating the test and taking a worst case.  The current test limit of 1,000 Pa mandated by Keymark is completely inadequate for windy islands like the UK, especially once safety factors are applied.  Manufacturers should test their panels to failure and declare the limit.

2. A water penetration test for roof integrated systems, taking into account each family of roof coverings (tile, slate) with which the panel works.

3. A single fire test, which works across Europe.  Currently there are four different tests in the "harmonised" European fire standard, and different national governments require different tests.

CEN is currently developing a new version of EN12-975 with the aim of including optional tests for weather tightness and fire performance.  This cannot come soon enough for european solar manufacturers.

(Incidentally, everything written above applies to the EN61215 durability tests for solar PV modules. MCS 12 covers both solar thermal and solar PV, whereas the CSTBat only applies to solar thermal.  For once the UK has beaten France by getting its barriers to trade in first, perhaps not something to celebrate.)

This article first appeared in Solar Business Focus UK, Vol 7-2013, sister publication to solarpowerportal.co.uk