I can’t believe that April is drawing to a close and I’ve not managed an update since the end of March. On the basis of my laziness I’ll save time a update the whole month in one go.

The first fix electrics are now completed and plumbing is to follow over the next couple of weeks. The scaffolding that is needed for inserting the velux windows into the roof, patching up the few slipped tiles, sorting out the gutters & ventilation and working on the two upstairs windows is in place. It’s really looking like a building site now.

Peak Oil is a notional point in time. It is reached when the rate of global oil production hits its maximum level from which the only way is down. In these terms downs means escalating costs of extraction & production, restricted supply, unfulfilled demand and increasing prices.

The foundations of the peak oil concept lie in the Hubbert peak theory of Marion King Hubbert that accurately predicted that United States oil production would peak in the early 1970′s. The term Peak Oil currently usually used in relation to world oil production as a whole. Conservative estimates place the date at which Peak Oil is reached at between 2020 & 2030, whilst more pessimistic commentators will suggest that the point has already been passed.

Whilst much of the comment and speculation around the subject reads like Princess Di or JFK conspiracy theorists letting their imaginations run wild, there are tracts of thought that can help us in consideration of designing our homes and living environments sustainably.

So what has this got to do with barn conversions?
Most obviously, restricted oil supplies lead to expensive energy. We are already being subjected to soaring energy costs and uncertainty (whether or not this is related to Peak Oil I’ll leave to you to decide). Under these conditions sustainable, self-contained energy solutions become attractive not just from a isolationist perspective, but also a financial one.

We must also consider the wider impact of oil supply as it extends its tendrils into so many other aspects of modern life. The plastics, chemical fertiliser & pharmaceuticals industries all rely heavily on oil. What alternatives are there and how can we insulate ourselves from the impacts of change? This question when coupled with the challenges of climate change has lead to the transition town movement.

A Transition Initiative is a community working together to look Peak Oil and Climate Change squarely in the eye and address this BIG question:

“for all those aspects of life that this community needs in order to sustain itself and thrive, how do we significantly increase resilience (to mitigate the effects of Peak Oil) and drastically reduce carbon emissions (to mitigate the effects of Climate Change)?”

Photo = light & voltaic = electricity

Photovoltaics is a technology that utilises light to generate electricity. As such it is an essential tool in the development of more sustainable methods of electricity generation. Simplistically, electricity is generated by the photons from sunlight colliding with electrons within the solar cell.

Solar cells are solid state devices that produce direct current electricity from light. They are arranged into interconnected groups to form a module. In turn photovoltaic (PV) modules are connected together into photovoltaic arrays. A module is big enough to power a single device with larger applications such as a family home requiring an array. PV arrays can be built into the fabric of a building, in its roof or walls, or developed as a stand-alone system as we see connected to street lights or on caravans.

PV cells use both direct light and indirect or diffuse light and so are effective even in temperate climates and operate under grey overcast skies, not just on bright sunny days.

As in most cases they constructed largely from silicon, the manufacture of PV modules has relatively green credentials, although the need for batteries for storage in off grid situations can somewhat sour this.

Most UK implementations of PV will be grid connected PV systems. In these systems there is no need for battery storage. The PV system is connected to the local electricity network (grid) and any electricity not consumed locally can be sold to the electricity supply company. Where the local PV system is unable to provide all electricity demanded, for example at night, then electricity is bought from the grid. The ‘grid’ acts as the storage system.

An inverter will be required to convert the low voltage (12 volt) DC electricity generated by PV to high voltage (230 volt) alternating current (AC) consumed by most UK appliances.

How much?
A typical domestic system will need between 1500 and 2000 Watts peak (Wp)
Typical modules have power output of 75 to 120 Wp.
Therefore, 10 to 20+ modules will be required.

I have ‘tirelessly’ searched the internet for illustrative costs from various sites and articles of various ages I’ve come up with the following prices each from an individual source:

£4,000 to £9,000 per kWp installed.

£8,000 and £15,000 on a typical domestic installation of 1.5 kW.

…this works out at £12 000 – £14 000 for a 2 kWp system for a house.

To provide a PV power supply capable of meeting the demand from a typical domestic energy efficient house costs in the region of £20,000.

…costs can be around £5,000- £8,000 per kWp installed with most domestic systems usually between 1.5 and 3 kWp.

Which gives an average of somewhere around £6,000 per kW so £10,000 for a typical domestic installation of 1.5 kW. As this will save you several hundred pounds a year on electricity costs the financial payback is long. The overall cost-benefit will only tip into the positive if you personally value the ecological benefits highly.

Beautiful things electrical cables… especially when they mean that you’re making some progress with the first fix.

Being a fan of lists, we’ve been using one to keep track of those items that we need to specify and decisions we need to make in regard to the detailed design of the conversion ~ attention to detail.

This is the current position:

• Ground or Air Source Heat Pump that is the question. >>
  Answer = Neither We’re now planning for a ‘simpler’ system with solar and multi fuel burner input. More on this soon.
• Heating. Go with under-floor heating on the ground floor with radiators on first floor ~ drawbacks, problems, source of hot water for radiators (potentially from back-boiler on multi-fuel room heater)?
  Answer = UFH with radiators on first floor. Decision made on grounds of cost and the unsettling prospect of all that scree suspended on the first floor!
• Internal doors (find some that we like).
  Still working on that one.
• Openings through internal walls. Have we allowed for one to few? – yes but we will replan the bathroom / bedroom entrances.
  Answer = One opening. I’m pretty pleased with the one opening as it has allowed us to plan in a dressing area and thus create a main bedroom ‘suite’. More on this soon.
• Paint. Compare eco alternatives to branded products.
  We love clay paint. Eco / Green ‘gloss’ paint review coming soon.
• Rain-water harvesting. Readdress the quote I’ve already had and evaluate cost and fit to the current plan.
  I’m going to save this one for phase 2.
• Flooring and tiling ~ select!
  We still need to decide on the main floor tiling for the ground floor, but I’ve already bought some slate mosiacs for the en-suite. We’ll use slate flooring in both bathrooms. The wall tiling in the main bathroom will be white, probably with wood panelling. More on this soon.
• Guttering and down-pipes excluded from bill of quantities, estimate and add them back in.
  This is one for later…
• En-suite bathroom~ what shall we do with the 1 metre dressing area.
  Sorted! See ‘Openings…’ above.
• Bathroom suites and Kitchen…
  Working on this one…
• Storage~ allow for narrow cupboards built into internal partition walls on the first floor.
  We’ve got a utility area in the kitchen, cupboards in the dressing area and second bedroom. So we’re getting there – the partition wall idea isn’t such a good one, although hopefully we can install shelving on the landing.

You see, we are making some progress.