Day Five began with the setting up of a grid tied system, which is commonly used in a house based solar systems. These systems are used to power household electrical appliances and when sunlight permits the eventual selling of power back to the national grid.
The set up connects solar panels and main grid together by way of a solar grid tie micro invertor. The invertor synchronises the voltages so that they are in phase and so they do not cancel each other out, if this happened there would be no power at all. With our example we used a lower mains current for safety purposes, but normally it would run on normal mains electricity. The system is set out as shown in previous diagrams and photographs and worked well. I measured the current flowing through the system with and without the solar panel being on.The current measured from the mains came out at 0.06 amps, from the solar panel 0.04 amps creating a total output of 0.1amps.
With solar energy harvesting being what it is at present, so much depends on the sunlight that is being produced. Some days you may get bright sunshine all day, on other days you may not get any at all, so this is where this system comes in. This system takes supplies from the mains on days where there is no sun and takes power from the solar panels on days where there is plenty of sunshine. If more power is supplied from the solar panels than is needed by a household any surplus will be sold back to the national grid,which of course generates extra cash and saves on household bills ,over a period of time.
Old (left) New (Right)
Because most household systems have several solar panels they are set up in such a way, so that any faulty panels or panels effected by shading do not totally stop the panels producing power. Originally the panels were made connecting each panel together; this meant if panel two stopped working so did the whole system. Over time and possibly through trial and error,the system was refined so that cells/panels could be isolated.
Sunlight as I mentioned is a crucial factor in solar power and as an example I’ve noted here the various weather conditions in lux to give you an over idea of the differences
|Moonlight Clear night||0.0001|
|Overcast Day (very)||100|
|Full Daylight||10,000 – 25,000|
|Direct Sunlight||32,000 – 100,000|
The rest of the day was spent making a database up of UK. Europe and worldwide solar companies and looking through trade magazines.