Emissions and the environmental impact of power generation is back in the spotlight, thanks to the COP21 World Climate Summit held in Paris during December 2015. In order to achieve the targets set by the agreement, there has to be a big shift away from traditional power generation towards greener energy production.
No power generation technology is entirely environmentally friendly. Hydro-electric power stations have an impact on water courses and impacts local wildlife. Wind turbines account for a number of bird deaths every year. Building hydro, wind or solar equipment also has a carbon footprint that has to be taken into account. Yet this carbon impact is a tiny fraction of the carbon footprint associated with more traditional power generation technologies.
Once installed, a solar electric system is a low-carbon electricity generator. The sunlight is free and the system maintenance is extremely low. There is a carbon footprint associated with the manufacture of solar panels, and in the past this footprint has been quite high, mainly due to the relatively small volumes of panels being manufactured and the chemicals required for the ‘doping’ of the silicon in the panels.
Thanks to improved manufacturing techniques and higher volumes, the carbon footprint of solar panels is now much lower. You can typically offset the carbon footprint of building the solar panels by the energy generated within 2–3 years, and some of the very latest amorphous thin-film solar panels can recoup their carbon footprint in as little as six months.
Therefore, a solar electric system that runs as a complete stand-alone system can reduce your carbon footprint, compared to taking the same power from the grid.
In general, the same is now true of grid-tie solar. In the past, the power companies have struggled to integrate renewable energy into the mix of power generation sources. This has meant that whilst the energy produced by solar panels was non-polluting, it did not necessarily mean that there was an equivalent drop in carbon production at a coal or gas-fired power station.
However, over the past few years, power companies have become far better at predicting weather conditions in advance and tuning the general mix of power generators to take advantage of renewable energy sources. This has ensured a genuine carbon reduction in our energy mix.
Of course, the sunnier the climate, the bigger benefit a solar energy system has in reducing the carbon footprint. In a hot, sunny region, peak energy consumption tends to occur on sunny days as people try to keep cool with air conditioning. In this scenario, peak electricity demand occurs at the same time as peak energy production from a solar array, and a grid-tie solar system can be a perfect fit.
If you live in a cooler climate with less sunshine, peak energy demand often occurs in the evening, when solar energy production is dropping. This does not negate the carbon benefit from installing solar, but if you want to maximize the carbon benefit of a solar energy system, you should try to achieve the following:
- Use the power you generate for yourself
- Use solar energy for high load applications such as clothes washing
- Reduce your own power consumption from the grid during times of peak demand
- Store some of the excess solar energy production using batteries and use it in the evening
Environmental efficiency: comparing supply and demand
There is an online calculator to map your electricity usage over a period of a year and compare it with the amount of sunlight available. Designed specifically for grid-tie, this calculator shows how close a fit solar energy is in terms of supply and demand.
Whilst this online calculator is no substitute for a detailed electrical usage survey and research into the exact source of the electricity supplied to you at your location, it will give you a good indication of the likely environmental performance of a solar energy system.
To use this online calculator, collate information about your electricity usage for each month of the year. You will usually find this information on your electricity bill or by accessing your electricity account online. Then visit http://www.SolarElectricityHandbook.com, follow the links to the Grid-Tie Solar Calculator in the Online Calculators section.