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One Tonne Life
Vattenfall

Tag: Electricity

Sun, wind and water

“Sun, wind and water – the best things in life” sang Swedish star Ted Gärdestad many years ago. The Lindell family’s electricity is produced from the sun and water. When the time came for them to choose which type of electricity they would use when the sun’s rays were not up to the job, the choice was between wind and water. Alicja wanted the family to go for wind, while Nils wanted electricity from water. In true family spirit they chose to start off with hydro-power and to switch to wind-power when the time comes to renegotiate their electricity contract.

Everyone is allowed to specify their preferred source of electricity – wind, water or nuclear power. Or a mixture of all three.

When I’m asked what I would choose, I always preface my answer with a brief description of how electricity is produced in different parts of the world and in Sweden. 68% of the world’s electricity comes from fossil fuels, 13% comes from nuclear power and 19% from renewable energy sources. In Sweden, which has an abundance of hydro-power, half comes from renewable energy sources and half from nuclear power plants and combined power & heating stations (district heating plants with electricity production or industries with electricity production). Two percent of Swedish electricity comes from wind-power.

And then I generally ask a question of my own: how important is it to you?

There are many ways to assess our energy sources. From the purely engineering viewpoint one way is to conduct a lifecycle analysis, that is to say calculate the environmental footprint from the cradle to the grave. Another is to just look at the environmental impact while the power stations are in operation. The environmental impact from electricity production differs between different power sources. Electricity production in Sweden has very low emissions of CO2 compared with the world average since we do not use fossil fuels.

Follow the example of the Lindells, choose how you want your electricity to be produced!

The photograph is from the Akkats hydro-power station outside Jokkmokk.

Lars Ejeklint, Vattenfall

You get what you buy!

When I buy macaroni at my local ICA supermarket, I expect the package to contain just that – macaroni. Which it always does. Furthermore, if I buy “Krav” eco-labelled macaroni I don’t expect to find that it contains traces of pesticides. There’s nothing particularly strange about any of this.

So how about when it comes to electricity? This is something one can argue about without end, and it’s into this hornet’s nest that I’m now stepping. The fundamental question to ask is whether electricity is special or not as a product. Electricity should naturally be regarded as a product just like any other. That is why regulations governing the guarantee of origin of electricity were brought in on December 1, 2010 (2010:601).  Put simply, this means that the company producing the electricity has the right to issue a certificate of origin for all electricity produced using a particular type of source. This certificate can be sold on but must be annulled once it reaches the end-customer so that it is not counted several times over. The aim of this entire legislative package is to support the use of energy from renewable sources. In the EU there is a directive on this issue which in Sweden was dealt with in government bill 2009/10:128 “Implementation of the Directive on Renewable Energy”. For anyone particularly interested in legislation, statistical data and legal texts, I recommend that you read this document in its entirety. For everyone else, what it all boils down to is that you get what you buy. Just as with the macaroni that I started off talking about.

That’s why it’s particularly important to see to it that you have a good agreement for your electricity. That is how you can be sure you are getting electricity with a small CO2 footprint and that you can make a significant contribution to cutting your CO2 emissions. For instance, Vattenfall’s electricity from hydro-power produces 6 g of CO2/kWh. If you recharge your Volvo C30 Electric with electricity from hydro-power, this corresponds to less than 1 g of CO2/km. The green-car limit is 120 g of CO2/km and the Swedish average for 2010 was 152.3 g of CO2/km (source: JATO)

You are probably familiar with the issues of marginal electricity, electricity from Danish coal-fired power stations and so on. These issues are very complex and should naturally be taken into account. But not by the customer. Marginal electricity is something that should be dealt with by the decision-makers and the power industry.

As the customer, you always get what you buy. That’s the law.

David Weiner, Volvo

What can you do with 0.15 kWh of electricity?

I live in south-east Göteborg and commute to Volvo’s Torslanda plant every day. That makes a round trip of 40 km a day. A Volvo C30 Electric consumes 15 kWh of electricity per 100 km in mixed driving conditions, so if I had a C30 Electric I would use about 6 kWh of electricity per day (for the 40 km daily commute). For the same distance, a C30 DRIVe would use 3.8 litres of diesel per 100 km, which means 15 kWh of energy. In other words, more than twice as much energy. This is because an electric motor is far more efficient than an internal combustion engine.

But the question was what we can do with 0.15 kWh of electricity. Drive a Volvo C30 Electric a distance of 1 km, for instance. But it is of course possible to use that power for other things too. The table below offers a few examples by way of comparison.

There are naturally considerable variations between different household machines. This can be seen, for instance, in the Siemens products with which the house is equipped – they are particularly energy-efficient. What is important to demonstrate when we now start using electricity to power our cars, is that the energy that we use in the house is also used for the car. So by how much will our electricity bill increase when the car runs on electricity? If the car is driven 15,000 km/year, it will consume about 2250 kWh. This corresponds to an increase of 10% in the average Swedish villa (22,000 kWh according to the Swedish Energy Agency).

The following table presents an interesting comparison between different fuels. 1 km in the Volvo C30 Electric consumes 0.15 kWh. This corresponds in terms of energy content to:

However, internal combustion engines have a much lower efficiency rating, so to cover 1 km they will require more than twice as much of each fuel, depending on the type of engine fitted. The exact figures for Volvo’s car range can be found at www.volvocars.se

David Weiner, Volvo

There’s a cat in the family’s car-port

According to the book “Time to Eat the Dog? The Real Guide to Sustainable Living” a cat has the same environmental footprint as an electric car. The environmental impact of a dog, on the other hand, is about the same as that of an SUV. And just as with us human beings, it’s the diet that is behind it all.

The family’s cat – sorry, I mean electric car – is a Volvo C30 that costs the family 950 kronor in electricity over a period of two months. For this money, they have driven 4,000 kilometres with virtually no burden on the environment at all. If they had driven their fossil fuel-powered car the same distance, it would have cost them between 3,000 and 4,000 kronor, with emissions of almost one tonne. The electric car does make a noticeable difference.

Lars Ejeklint, Vattenfall

The house’s solar cells

The Lindells have solutions that will make things easier for them on their journey towards one tonne of carbon dioxide emissions per person per year. One of the challenges the family are facing is to reduce their electricity consumption. In order to further cut their energy usage, the One Tonne Live house will produce its own energy. Firstly via solar heating and secondly via solar cells that generate electricity. The electricity is produced by the house’s own solar cells which are fitted on the south-facing roof and façade. This electricity is used by the Lindells for cooking, recharging the family’s electric car and for powering other equipment at home. The solar heat that the house stores will produce most energy while the house is empty, for instance during the day while everyone is at work and school or while they are away during their summer vacation. Since solar heating produces a surplus of electricity, this will be fed into Vattenfall’s grid, with a corresponding amount of electricity fed back into the house when the sun is not shining.

The cells, made by Sulfurcell, are what are known as thin-film solar cells. All told, the One Tonne Life house’s 96 square metres of solar panelling will produce about 5000kWh/year in a normal year. Factors that affect actual output are how sunny the weather is during the year, the angle of the panels facing the sun, and the direction they face. The geographic location of the house itself is also a major factor – a house in the southern Swedish province of Skåne will produce more electricity than one in Norrland in the north of the country.

There are several different types of solar cell technology and thin-film is one of them. The advantages of the thin-film solution are its design and the fact that it creates a uniform, neatly integrated impression, as well as its price. This is an important consideration in order to recoup their cost over the years.

Christian Axelsson, A-hus

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