Gorgeous Green House

The Renovation Journey of a 1940’s ‘Traditional’ to 2015 ‘Contemporary, Green & Gorgeous’


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SOLAR ENERGY: WHAT DOES IT COST? HOW TO EXPLORE FEASABILITY

So What’s the Problem With Eskom Power?

We’ve all been grumbling in recent years at Eskom’s unreliable provision of electricity and are aghast at recent tariff increases.  Brace yourselves; Eskom is targeting an average annual increases of around 15% for the next five years.  The rate you per kWh depends on how much you use.

Figures from ESKOM website

Yet compared to global consumers our electricity bills are cheap.  Europeans for example are paying 4 times as much.

Coal is the most polluting energy source on the planet, and the main cause of the world’s CO2 emissions. (In addition it spews out nitrous oxide (N20), hydrofluorocarbons (CFCs, HCFCs, and HFCs) and methane (CH4). These emissions trap the sun’s heat and warm the planet, adding to the earth’s natural greenhouse effect. Coal ash, the solid waste produced contains large quantities of toxic metals, including mercury, arsenic, beryllium, cadmium, chromium, nickel, and selenium.

South Africa is the world’s fifth largest producer of coal, and is the sixth largest consumer on the planet.

The reality though is that the price we pay does not reflect our real cost.  South Africa’s addiction to coal generated electricity (only 1% of our electricity is coming from renewable resources) has other externalised costs including the following:

  • Acid mine drainage
  • Air pollution
  • Polluted water, massive use of water in production
  • Tunnels causing instability
  • Coal miners and local communities health and high mortality rate
  • Environment and eco-system degradation from the physical process of extracting the coal
  • Long term environment and eco-system degradation as a consequence of the greenhouse gases produced.

The University of Pretoria’s Business Enterprises unit has just released a report entitled The True Cost of Coal which clearly outlines the impact of continuing on this path.  The projected externalised costs (the ones that don’t appear on your utility bill) for the proposed new Kusile mine alone are a whopping R60.6 billion (766,656,000.00 USD) a year! The same report outlines the benefits of the transition to renewables, including far greater job creation and potentially faster provision to communities who are as yet not connected to the grid.  There are still 10 million South Africans without power (nearly 20% of us) and the technology is here to do it clean and safely.

But….How Much Will it Cost the Average Household to go Solar?

Before answering that question I urge you to look at your current energy costs.  Scrutinize your electricity bill.  Look at how many Kwh you are currently using.  The Eskom table above could be a little misleading as my family is currently paying R1.02 (0.12 USD) per kWh. Calculate what you will be paying based on a 15% annual increase over the next say 10 – 15 years.  Try not to fall off your chair in a dead faint!

Eskom have a nifty calculator on their website that allows you to drop in your current kWh consumption and it shows you what you are paying and how much you will pay next year.  Go to http://www.eskom.co.za/c/53/tariffs-and-charges/ and click on the residential tariff comparison tool.

I worked out that if my family were to continue in our current very non-green house with our current shocking consumption of 1664 kWh per month our electricity spend over the next 10 years   would    be in the region of R694 995.93 (80367 USD).  Over the next 13 years    R1 236 697.00 (143 013.00 USD). Your own calculation may well provide similar impetus to explore alternatives! So clearly ‘dirty energy’ is costing us at all levels, but it still boils down to ‘what can I afford now’?

For several years I’ve had a minor obsession with the notion of ‘getting off the grid’.  I would ask vendors at Sustainability Expo’s and the like “how much for a family of 5 to set up to get off the grid”?  Five years ago the response would be a sorrowful shake of the head and responses like “maybe just aim to get your water heated and supply your lights”.  If I pushed the numbers ranged around the 1 Million Rand (116 000.00 USD) mark.  Fortunately the cost of photovoltaic (PV) cells is falling fast and some say that they will be at grid parity with Eskom by 2015.  (David Lishitz: Our Power Station).

I’ve been researching options, talking to vendors and doing some sums.  I recommend that you talk to   www.solarsunsa.co.za   who will walk your through the minefield of technicalities to help you understand your options.  Please beware of the plethora of inferior imports.

I’ve worked my calculations based on an annual consumption of 6694 kWh which is feasible if you make some changes.  For example, just switching to a solar geyser or heat pump can reduce your use by 40%.  (Note:  I plan to post a lot more all options to reduce energy consumption, including the hotly debated solar geyser vs heatpumps issue!).

The bottom line:   to get 97% off the grid your costs (panels, inverters, batteries, display screen, controllers, installation/labour etc.) from a reputable provider will cost approximately R340 000.00 (39317.92 USD).

I know, I know!!!  It’s a massive amount of money but if you plan to be in your home for a while you will get your money back by year 13.5 and thereafter you are laughing.  Remember the 15% increases we are promised? The scenario in the previous paragraph plays out like this:

So sadly, it’s clear at this point that only the wealthy can afford to make the investment (and benefit from the longer term payback) but is this not true of most investments?  Perhaps this is the way to view the opportunity?  My sense is that if industry, government and private households just get this thing started volumes will drive costs in the right direction, enabling more and more people access, encouraging further price reductions etc.  What will also create incentive is the ability to ‘sell back’ our excess energy when we have more than we need.  This is standard in other first world countries so fingers crossed we will catch up soon.

So, if you’ve got the means to make this investment and want to look at the viability for yourselves where to start?

Designing Your Solar System

Assuming you have already reduced your energy usage via the usual switch to LED’s, energy efficient appliances, solar geysers/heatpumps, general energy conscious living etc. start talking to vendors in the industry about how they would put together a system for you and what the costs would be based on your kWh consumption. Ask for a range of quotes to take you from 60% – 95% ‘off the grid’.

Battery Enclosure

You need to have a place to put your panels, and batteries, display screen and converters etc. That all needs to be planned for and a good specialist should advise.  You will need an outside cupboard that is well ventilated.

Most vital to the success of the technology will be the amount of sun you are in a position to harvest.If you are concerned that your intended roof/wall/garden space gets too much shade you

Solar Pathfinder

can ask you vendor to install a Solar Path Finder to calculate how many kWh of energy you will be able to harvest at all months of the year. The first design of our Gorgeous Green House had the panels positioned in the shade of an ancient Albizia adianthifolia (Flat Crown tree), not good! Trevor Wheeler www.solarsunsa.co.za  climbed up on our roof to put the Solar Path Finder in 3 places to take readings for us so we are now confident that our roof now facing North East is going to be right.

Don’t be put off if your are retrofitting and you roof line is wrong.   One can get creative and brackets can be used to place them just about anywhere as the link shows:  http://www.youtube.com/watch?v=vC-Xb3uaTk0

IOL Business Report SA Time: Fri Oct 05 2012 11:21:33 GMT+0200 (South Africa Standard Time) http://www.greenpeace.org/africa/en/News/news/The-True-Cost-of-Coal/

(http://www.precaution.org/lib/08/prn_is_coal_green.081106.htm) ( World Coal Association. 2010. Coal Statistics. http://www.worldcoal.org/resources/coal-statistics/


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Lose the Lawn!

In 2007 NASA identified grass production as the number one agricultural group in the US at a staggering 23 million acres.  The second-place cultivated crop was corn at seven million.   I couldn’t find any equivalent figures for South Africa but I do know that we love our lawns and I wonder why.

Lawn requires more water, fertilizer and weed and insect treatment (and work) than other parts of the garden. Grass is also mono culture and as far as attracting wildlife to your garden it has little to redeem it.  Using chemical fertilizers and pesticides have a horrible environmental impact.

Hibiscus praetuertus

Why not consider converting some of your lawn to a veggie garden or to planting more indigenous (native) bird and other wildlife attracting plants in your garden? Using your lawn as a small rug in the garden and not the carpet will change the way the space looks, feels and impacts on your local ecology. In addition you will save money on your water and fertilizer bill.  It will be a safe for children and pets and your will have a reduced dependence on lawn mowers and their maintenance.  Think also of the time saved!

At my Gorgeous Green House there isn’t a massive amount of lawn, but more than I want and I immediately need to create beds to propagate plants for the roof and vertical gardens. Digging up lawn is backbreaking work and you never seem to get all the roots out.  This is an old permaculture technique that works a treat and really is the easiest and greenest way to lose the lawn.

Well watered cardboard. Thanks Vusani

1.  Layer down some cardboard (you can also use newspaper). Water it to soggyness. This layer kills the grass and weeds by blocking sunlight, adds nutrients to the soil as weed matter quickly decays beneath the barrier, and increases the mechanical stability of the growing medium.

2. Add an approximate 10 cm thick layer of compost.

3.  Add some further woody and leafy matter, wood chips etc. If you have access to manure, fantastic!  These layers are now encouraging favourable soil microbial activity and worms and enhancing soil structure

Additional mulch

4.  Continue to keep moist

5.  In a few months the layers will have disintegrated and you are now ready for planting.

Rich, grass free soil ready for planting

Your plants will get a fantastic start often leading to improved resistance to pests and diseases and your garden will always be filled with the sounds of nature, bees, birds and butterflies. .