Friday 26 October 2012

Electricity prices are rising so install a green roof

Today I arrived home from work to a seasonably chilly house and a husband who's mood could only be described as icy....our electricity supplier has announced an 11% price hike and he's not happy.

So what does that have to do with green roofs?

Newly installed green roof just begging to
have PV panels added
Well, to start with, a green roof is a fantastic insulator, keeping a building warmer in winter and cooler in summer so savings there on the heating bills.  I speak here for the lucky souls who happen to have "greenable" roofs on their homes.  Our house was build long before electricity, let alone green roofs.  It has a steeply pitched, tiled roof and although it's strong enough to support a green roof buildup, the installation and maintenance would be a nightmare.  So, until we retire into something more suitable, there'll be no living roof on our house to help save electricity; 

So what about generating our own power with solar panels?  My friend Ginny and her husband Chris swear by them.  Chris installed PV panels on their roof in Essex and when they moved to the depths of deepest Norfolk, the solar panels came too.  Apparently the solar panels provide all the hot water they need in the summer months so the only fuel they use between late spring and mid-autumn is for cooking, boiling the kettle for tea and maybe watching a bit of telly.

Again, hubby says PV panels won't suit the look of our pretty house, BUT, being a farm, we do have outbuildings and so maybe he'll be persuaded to put use at least one of them to generate our own power and show the electricity company what he thinks of their pricing structure.

If however, he installs PV panels in conjunction with a living green roof, we'll be quids in.   Solar panels work best when the temperature is below 30 degrees celcius. Of course on a roof, in summer, temperatures can rise a lot higher than 30 degrees, thus rendering the PV panel less efficient; but if it's a green roof, the cooling effect of the plants will keep the temperature more comfortable and the PV panels will be more efficient.  PS...remember to design the roof so that panels are not casting shade over the sedum plants..they don't enjoy being kept in the dark

Research in Germany compared  PV cells over a green roof  with cells over Bitumen roofs. In over 5 years of recording, the panels over the green roof showed an average 6% increase in yields

I like it! So here I am, in my kitchen, log-fired Rayburn creating a nice warm fug around me.  Laundry is drying on the clothes horse in front of the fire, kettle is whistling and I'm wondering how I can persuade my dearly beloved to leave the comfort of the armchair to climb on the roof, install some Enviromat and wire in some PV panels before electricity prices go up in December.  I'll let you know how I get on.

Oh....if you fancy a green roof yourself, drop me a line and I'll send you a copy of our "how to" guide and a phone number for our installation man in case you'd rather sit by the Rayburn and let someone else do the work (like me)