By: Sara teknikvetenskap, Madelene design, David teknikvetenskap & Elias programmering

We have worked with solar power parks and the purpose with this project is to get a better understanding of how we can change our world in a positive way.

The biggest sun park in Norden

In the beginning of 2014 Nordens largest mobile solar cell park ”Megawatt parken” was installed in Västerås. It contains 91 solar trackers that generates renewable energy that covers the need for 300-400 households every year. The pphotovoltaic power station has an effect of about 1 million watt. The solar trackers are mobile and can therefore follow the lightest parts of the sky and thereby utilizing the sun to a maximum. The park is located along E18 between Västerås and Enköping and it covers a ground area of about 40 000 square kilometer.

Mälarenergi Kraftpojkarnas ”Solar park”

How does it work?

Solar (or photovoltaic) cells convert the sun’s energy into electricity. Photovoltaic cells are made of special materials called semiconductors such as silicon. Basically, when light strikes the cell, a certain portion of it is absorbed within the semiconductor material. This means that the energy of the absorbed light is transferred to the semiconductor. The energy knocks electrons loose, allowing them to flow freely. With this an electric current appears that you can either use to warm up houses ore produce warm water. Many solar cells are used for warm up swimming polls camping’s and sport fields. 

Resources 

The access to solar power is endless it’s only the weather that is a problem especially up here in Sweden. When we need the power the most in the autumn and winter we have almost no access to the sun and in the summer when the sun is up we don’t need the power as much. In Sweden we have about 1500-1800 sun hours per year, the worlds sunniest please Yuma a town in Arizona, USA has 4 015 sun hours per year. So in these areas where the sun almost always shines is the perfect place to install new solar power parks.

Price

solar cells are very expensive since the effectiveness is no higher than 12%. Solar power is however a good opinion fore places were the electricity consumption is not that high and are located aside from society such as the mountains and the archipelago. Here it would cost more to draw electricity to these places than install all solar tracker. The solar technology is however on is moving forward and there are many attempts to produce more effective and low-costing systems. Solar power requires a lot of capital investments when there are built but in the long run it will pay off. 1997 the government grant for 25% of the investment cost for solar power was taken away but today you can once again apply for financial support to build solar trackers but they have to meet some quality standards. You can apply for this grant at Länsstyrelsen. The price for a complete solar panel system including a hot water storage tank and the work lies around 60-70 000 Swedish crowns. The energy exchange lies around 4000 kWh for a solar panel with the measurements 10 m2 and the life span are 25-30 years. 

Material

A solar cell are made of a thin metal plate. The metal is always a semiconductor usually silicon. The plate is divided into to shifts, one is positivity charged and the other one I negatively charged., between the shifts there is an electric field. When the sunlight hits the plate a electric current occur. It is common that you link together several solar cells and store the energy it produces in a battery. It exist very big solar power parks and the biggest is located in München and contains numerus of solar cells. Solar cells creates direct current and to connect in the direct current into a power distribution grid you have to convert it to AC. Solar cells are most used on places far from electricity grid. They are always used on satellites but also on lighthouses, traffic lights and radio stations.  Electricity from a solar cell is expensive but many works on making it cheaper. Sweden is in the leading edge when it comes to development. When the production of solar cells increases the use of photovoltaic power plant will be more profitable and more people are going to begin using it. 

Negative impacts

The most common and most significant limitation on the use of solar cells is that the method is one of the most expensive forms in order to extract green energy. Another disadvantage of solar energy is the initial cost of the solar cells. Solar energy can only produce electricity during the daytime. This means that approximately half of each day, the solar cells produce no energy for your home. One solution is batteries which store the energy until the next day. You always need a source of energy additional to pass the winter time when the solar energy does not have the capacity to meet the house needs.
The weather can affect the efficiency of solar cells. Pollution can also be a disadvantage for the solar energy, as pollution levels can affect a solar photovoltaic efficiency and this could be a disadvantage for the company or industry wishing to install solar panels in heavily polluted areas, such as cities.

Future plans

At a global level there are scientists, researchers and companies working hard to make the future of solar power better, cheaper and easier to use. Currently only around 0.5% of the total amount of energy produced in the world comes from solar power, but solar energy is just like other renewable energy sources on the rise. By 2050 estimates the international energy agency IEA that solar energy will account for as much as a quarter of the earth’s energy production.