Hibrid facilities like the ones which we all have seen on Spanish roads, plus facilities that have been made by owners who have put their own money, to see how costly it was to bring the utility line of duty.
But besides this type of remote installations, where storage is present, you also could consider, as in many other parts of the world, to combine both technologies in On Grid installations, using and making profitable the same resources, you can get scale economics. While this may in some cases incur a small loss on the premises, by the interaction between this two technologies.
It is known that the hibrid site construction (solar and wind) complement each other better than it looks, but make a small summary of some of these synergies on why this happens:
• A wind farm site has surfaces on which you can install an additional photovoltaic plant.
• The combination of photovoltaic and wind systems, can make the same resource of land occupied, can produce up to twice as much electricity, while it was found that the losses caused by shading of the turbines are just only considered to be at the order of two percent at most.
• The construction of such plants hybrid energy does not require network expansion because these plants generate wind and solar energy at different times, which means that the level fed into the grid is more stable than wind power plants and photovoltaic alone.
• The effects on power grids, this type of facilities photovoltaic and wind energy in electricity networks, both global and regional level, makes these networks behave in a much more stable, because while producing wind turbines much more electricity during the coldest parts of the year, due to higher levels of wind over the winter months, the solar power plants generate more energy in summer, offsetting lower production of wind energy at this time of year.
• Losses wind shading on photovoltaic installations are minimal (evidently for that are also the designers).
• The common elements that will be used by each facility, such as network connections, authorizations, driveway, mains power evacuation, …, will lead to significant cost reductions, in addition to the aforementioned stabilization of energy production.
But besides synergies, when seeing the whole project, also a series of mutual interactions between the two facilities will be taken:
• The integration of the PV plant within the wind, generate a reduction of wind speed and wind profile disturbance, and consequently the energy production of the wind farm decreases, although very little.
• In the interaction of the wind farm on the PV system must be taken into account among others, the following topics:
- The slopes of the available areas
- The own shadows on the horizon
- The impact of shadow generated by wind turbines
But all this can be a good project circumvented in some cases, taking into account the effects of possible stabilization in production, mixing the two types of technologies, as we will have:
• wind during winter, while solar radiation is low but very efficient production in sunny days due to less cell temperature
• wind during the night, when there is obviously no radiation
• wind during the rainy and cloudy days, while radiation is low
• Good radiation on sunny days, when we anticyclone, and we have wind
A profit will also be in Capex (capital expenditure), due to the synergies between the wind farm and photovoltaic system:
• Cost of installed electrical equipment
• Cost of energy networks evacuation
• Costs of civil engineering works (access, roads …)
• Cost of land lease
• Stabilization of the energy produced
All this should be compared with revenue losses already mentioned, when they are operating the two facilities, due to the loss of energy production, as losses due to the PV system, can cause a loss of income below 1 5% by photovoltaic systems, and losses in the turbine, can also cause a loss of income below 2% (compared with independent photovoltaic plant, according to some studies consulted).
The study should be complete and contemplate:
- The mutual interactions
- Annual degradation modules
- Rates
- Discount rates
Say that, although it seems that there are lights and shadows, international experiences made are positive. And in the future framework for distributed generation and smart grids, making the generation is stable, and that fits as far as possible to demand, will make use of existing networks and lower requirements Additional investments are to collect more and more important. Not to mention that in some cases it is not possible to perform short-term lines due to environmental problems.
It is for all this, so important to conduct this type of hibrid facilities, with only renewable technologies, for cases of small isolated facilities to small and medium connected to network an important consumption facilities, and avoid the use of large MW existing sites, where the combination of the two technologies can lead us to some technical and economic synergies.
