Everyone’s talking about renewable energy and we all know that if we’re really serious about sustainable living and low carbon lifestyles, then it’s the way to go.
Wind, wave, solar or biomass – whichever one you choose you’re doing your bit, right? But that’s the thing – which one do you choose? We know each of them is supposed to be a great idea and we all ought to be installing them if we possibly can, but how do you know which is the right one for you?
In fact, when it comes down to it, how much do you know about renewable energy?
Are you an absolute whiz on all the renewable technologies, or do you struggle to tell your hydro-electric from your photo-voltaic?
Try our quick quiz and see how much of what you’ve been hearing has really sunk in.
Contents
1. What’s the minimum recommended average wind speed…
needed for a home wind turbine?
- a) 0.5 metres-per-second
- b) 5 metres-per-second
- c) 50 metres-per-second
2. ‘PV’ is one form of renewable energy…
but is it:
- a) A way of recovering waste heat from a partially vented combination boiler?
- b) A method of generating low-energy light?
- c) A means of producing electricity from sunlight?
3. How does a tonne of wood compare with a tonne of coal as a fuel
- a) 20% as much energy as coal.
- b) 60% as much energy as coal.
- c) 90% as much energy as coal.
4. How does a ground source heat pump work?
- a) A liquid-filled loop takes heat from the soil and a heat pump makes use of it.
- b) It takes heat energy from hot rocks in the earth’s crust.
- c) Hot water is stored in a big underground tank underneath the house’s foundations.
5. For solar water heating, how large an area of panel should you allow per person?
- a) 1 square foot.
- b) 1 square metre.
- c) 10 square metres.
6. How does the amount of energy reaching the earth from the sun compare…
with the amount of power consumed by the world’s population?
- a) 6 times more.
- b) 600 times more.
- c) 6,000 times more.
7. Do you need planning permission to install renewable energy systems?
- a) Yes, always.
- b) No, never.
- c) Sometimes, it depends on what you’re installing and where.
8. Your turbine installer tells you that you are going to need an ‘inverter’
– but what does it do?
- a) Turns the direct current (DC) generated into alternating current (AC) for use in the house.
- b) Allows the turbine blades to spin backwards to generate more power.
- c) Lets you turn the turbine over to avoid it becoming damaged in high winds.
9. What is ‘Short Rotation Coppicing’?
- a) A kind of propeller used in small-scale hydro electric power systems.
- b) A method of growing trees for biomass fuel.
- c) A type of short-bladed wind turbine designed to save space.
resource belongs to the UK?
- a) 40%
- b) 20%
- c) 10%
11. What is meant by ‘embedded generation’?
- a) Generating power close to where it will be used.
- b) Generating power from a ground source pump buried in a charcoal bed.
- c) Generating power centrally and distributing it over the National Grid.
12. How much fuel would be needed to heat an average home using a wood-burning stove/boiler?
- a) 140 tonnes of wood chips a year.
- b) 40 tonnes of wood chips a year.
- c) 14 tonnes of wood chips a year.
Answers
1. It’s (b); the Energy Saving Trust only recommends installing a turbine if the yearly average wind speed in your area is more than 5 metres-per-second.
2. PV – ‘photo voltaic’ – produces electricity from light; the answer’s (c).
3. (b); weight-for-weight, wood has around 60 per cent as much energy as coal.
4. It’s answer (a); the heat comes from a buried loop in the soil.
5. Answer (b) – 1 square metre per person, according to the Centre for Alternative Technology.
6. Incredibly, the answer’s (c), nearly 6,000 times more. Around 90 petawatts (that’s 90 quadrillion watts!) of sunlight reaches the earth’s surface; humans consume an average of 15 terawatts (a mere 15 trillion watts by comparison) of power!
7. It’s (c), it depends on what you’re installing and where; some of the technologies will need approval and the rules for listed buildings and houses in conservation areas are different, so you need to check with your local council to be on the safe side.
8. The answer’s (a); inverters turn DC into AC.
9. It’s (b), a way of growing trees, especially willow and poplar, for fuel.
10. Britain really is a windy old place – it’s (a), 40 per cent.
11.The answer is (a), generating power close to where it will be used.
12. It’s (c). According to the Energy Savings Trust, a 20kW boiler would need around 14 tonnes of wood chips (or seven tonnes of pellets) yearly.
So, How Did You Do?
- 10–12 Fully charged!
- 5–10 Pretty sustainable!
- 0–5 A bit off the grid!
The phrase “amount of power consumed by the world’s population” should be “amount of energy consumed industrially …”. The most important part of the energy supplied by the sun, that the earth’s living population (plants, animals, bacteria, etc) uses is that used as photosynthesis, at an efficiency of a few percent, or is it less than 1%? The next one, used by all terrestrial life, is the conversion of seawater into fresh water, and its transportation over land. Again, the process is wildly inefficient. The water is evaporated, it rises a mile or more, and condenses again, sending most of the energy out into outer space. But this process, including the part that powers hurricanes, is essential to prevent the Earth’s becoming even hotter. The total amount of radiative energy that the Earth receives has got to be lost again, at the same prodigious rate, or the globe gets warmer. The anthropogenesis of global warming is not our production of heat, it is the production of gases that tend to hinder the process of getting rid of the energy impinging upon our planet.