I am also thinking of going solar but want to understand more about shading - we have trees that shade for about 3 - 4  hours a day. Is it possible to have panals independent to reduce the impact of this. One option could be to have a 1kwp panel on the flat garage and another 2 kwp on the house roof (when one is shaded the other is getting the sun) does this mean 2 inverters etc. The garage is separate from the house but does have a current energy supply. So can separate panels feed into the same inverter? and any advice about the type of cells and the type of inverter would be greatly appreciated. I am thinking of the hybrid types.  And what other electrics is involved - have people fitted their own export meter? My electric company says it would make an approximation of how much energy I had produced which seems a bit random.
CotonH

Here's a thought arising from the item on dishwashing in last weeks imeasure email.



Is it better to hand wash or use a dishwasher?

The Guardian Green Living blog has revisited this long standing
question and provides some estimated carbon foot print figures.
Careful hand washing with only a sparing use of hot water has a lower
carbon footprint than using a fully loaded dishwasher. However most
people are not as careful with the hot water as they could be and
using too much can push the hand washing carbon footprint well above
that of the dishwasher.

View the full blog post and figures here
<http://www.guardian.co.uk/environment/green-living-blog/2010/aug/19/carbon-footprints-dishwasher-washing-up>


It could be that what makes the difference is what you do while the dishwasher is working!

I figure that if I can get the teens to do the washing and drying then that is time that they are not spending in their 'caves'  beeping and buzzing with all their electronic gizmos.

The alternative is that I load the dishwasher and then go watch the TV!

MarkTime
.

I'm not sure if solar is a good option for me at this time or not. I currently use (on average) 4.5kWh per day, any opinions weather i should invest in solar or not?

Huw

Not as bad as you might think.  I have previously estimated the carbon cost of a return flight to near-by Europe at half a tonne CO₂, including a factor for high altitude effects.  They occupied 4 seats so their impact (based on average for all flights) is 2 tonnes for the holiday to Spain.  (Source: www.coinet.org.uk/walking-walk)  The newspaper article says the carbon cost of heating went down from 9 to 3.2 tonnes, which is a saving of 5.8, leaving a net 3.8 tonnes of CO₂ saved.

To curb the flights, how about a Marketing Tax?  All marketing budgets to be taxed according to the carbon intensity (in kg CO₂/£) of the product they are marketing, and the relationship of tax rate to carbon intensity to be logarithmic, not linear.  If only it were possible!

On the 16th of August, we posted in the imeasure newsletter a link from the Telegraph newspaper about energy-from-waste plants.

The article outlined the Government plans for a zero waste Britain. This means that useful rubbish will no longer be sent to landfill. Food and other biodegradable waste can be incinerated and used to produce electricity. There is often opposition to these power stations from local residents on the grounds that they are unsightly and produce dangerous gases. The government has suggested reducing energy bills for people living near these plants as a method of compensation, a practice already common on the continent.

Read the full story at http://www.telegraph.co.uk/earth/earthnews/7917168/Cutting-waste-to-landfill-will-mean-incinerators-and-slop-buckets.html.

Imeasurers got in touch and the comments were so interesting that I could not resist opening a new thread in the forum to open the debate further.

Here below are the comments we received so far:

imeasurer 1 from Oxfordshire, on Monday the 16th of August 2010:

"Sorry to put a damper on this, but reducing the energy bills of those living near a new incinerator sounds like bribery and 'divide and rule' tactics to me.  Locals (and non-locals) have very good arguments against incineration, and the rest of the population are indifferent (or at least silent).  Offer reduced energy bills, and the local community might then be divided, leaving the incinerator company with a better chance of clinching the deal.

The Telegraph article is superficial and sometimes wrong! e.g. it says "The UK has to reduce landfill by 75 per cent on 1995 levels by 2013 or face billions of pounds worth of fines from Europe."  Actually it has to reduce *biodegradable* waste to landfill by 75%.  An interim target was to be met by 2010, and Oxfordshire will meet it entirely through recycling and food waste collections.  They used to threaten us with these fines if the incinerator was not built by 2009.  The food waste will go to in-vessel composting or to a different kind of energy from waste plant, an anaerobic digester.

The residual waste still needs to be diverted from landfill, because the rate of landfill tax (different from the fines) is escalating each year.  Incineration is a stupid and inefficient way of dealing with it and produces precious little electricity.  It burns fossil fuel in the form of unrecyclable and unrecycled plastic, it creates new hazards in the form of 'persistent organic pollutants' such as dioxins and furans, and it is so capital intensive that it needs a 25 year contract to be viable.  There are other more benign methods of dealing with residual waste, which increase recycling a little further (thus saving a load of embodied energy, energy that would otherwise have to be used to make virgin materials from scratch) and has more respect for the atmosphere, and no newly created toxic waste to deal with.

Sorry.  I've been angry about this since the county started "consulting" on this in 2004!

Your newsletter is very useful - indeed a few weeks ago I was able to let some London friends know about a guided tour of eco-renovated houses that you covered.  They were very pleased to hear about it and went along."

imeasurer 2, on Monday 16th of August 2010:

"It was very disappointing to read that the government plans food and other biodegradeable waste make no mention of using them if feasible initially as feedstock for AD plants, instead of just incineration.  Furthermore, there would probably be less objections as well, besides the beneficial by-products of very good fertilisers for farms or compost users.   They should be taken to task on this right away!"

We are now opening the floor for more interesting comments and point of views. So do not hesitate to add to the debate! It is always great to hear from you!

Muriel

 

On imeasure D is average for imeasure and  C is up to 39% less than average, so I guess  - bell curve - nearly half of us are there.

take a look at Jevons paradox
http://en.wikipedia.org/wiki/Jevons_paradox
http://www.socialtext.net/brightgreen/index.cgi?jevon_s_paradox

Yes black-dog , lucky them .

I'd have like to seen the money spent on reducing demand rather than a alternative heat source  ( though in this case clearly more effiecent in its use of energy)
Even so Jevons paradox applies , tricky problem .

Savings could also be reinvested in more energy effiecency = more money saved = more holidays , perhaps The only solution is heavy handed green taxs making the financial cost balance with the true environmental cost
State control over market forces, cant see that happening.
Sorry no more cheap flights allowed !

I have just clocked up my third year's worth of data and am showing impressive savings.

Gas usage down 9% and electricity down 17%.  Even more impressive is my carbon saving as I have installed solar PV and my net electricity import is down 40%.  Carbon saving is 14%.

There should be more savings in the next year with a full year's output from the solar and the benefit of some internal wall insulation I am installing on my solid wall house.

Blackdog - is there any way of seeing how my saving compares to that acheived by the average of the entire I measure population?

Well lucky them for having the system installed by the housing association.  Holidays would have been off the agenda for a good few years if they had had to stump up the £5,000 - £6,000 installation fee!

Hello, I am a researcher at the Environmental Change Institute, Oxford, and I was just wondering what people thought of the imeasure newsletter story of last week about the Pearce family who, having installed an air source heat pump, saved so much money on their energy bills they were able to fund a holiday to Spain.

Again, the story link can be found here: http://www.thisisoxfordshire.co.uk/news/8266101.Family_slashes_heating_bills_to_pay_for_dream_holiday/

The practice of spending money saved through energy efficiency on something that uses more energy, so that initial savings are reduced or cancelled out, is a phenomenon called the 'rebound effect'. The Pearce's story is a classic example of this - and not surprising as they were clearly motivated by economic rather than environmental factors. It is a really tricky issue and one that makes it very difficult to measure what improved energy efficiency actually achieves, given that we don't know how money saved is spent.

We have had a few comments from i-measurers on this, which are below. So we decided to take the issue to the forum and ask whether anyone have any more comments, and in particular any ideas for how to manage this difficult issue?

Comments so far:

i-measurer 1, on 27/07/2010:
"Did the family fly to Spain?!?"

i-measurer 2, on 27/07/2010:
"I don't wish to play devil's advocate too strongly, but isn't your story about the Oxfordshire family a perfect example of why saving energy is pointless with our current mindset?  Every pound saved on heating our homes gets spent on another carbon intensive product - e.g. flights to sunny Spain.  The UKERC report on rebound effects highlights this problem nicely - http://tinyurl.com/3yk5qha

While I like your project's aim to educate consumers and improve the data sets available to researchers, I hope you won't be promoting the ideas of buying a bigger car or flights around the world with the money we save - otherwise you can expect a net carbon saving of 0..."

Thanks,

Bex (research assistant, ECI)