Page 465 - A Comprehensive Guide to Solar Energy Systems

478 A ComPREhEnSIVE GuIdE To SolAR EnERGy SySTEmS

will result in a major deployment of solar power across the world in the coming 5 years.
Whether we reach 1 TW of installed solar, the rate of deployment will undoubtedly acceler­
ate. Therefore, solar power is set to become a growing part of the electricity system of all
countries in the world and is on track to meet the IEAs prediction that by 2050 solar will be
the world’s number one energy generation source.

24.4 Segmental Growth

In terms of the segments that can be identified in solar, there are three distinct types of
installation: utility scale (solar farms), industrial/commercial, and household. The latter
two are almost all entirely roof top based and thus some commentators often make a split
between rooftop and ground mounted solar power [1]. For the purposes of this chapter,
the delineation will be made between rooftop and ground mounted utility scale for sim­
plicity of expression.
To date, a common model of solar development in most countries has been to start with
large­scale ground mounted solar and to slowly develop the rooftop segment alongside
the utility scale solar [1]. The global leading solar markets all started in this way: China,
the united States, Germany, and the united Kingdom for easy examples. The trend that
can be discerned is interesting, as in these markets the utility scale solar develops through
stimulation normally caused by incentive schemes, and once the large­scale solar is up
and running, rooftop solar begins to speed up in deployment.
There are many potential reasons for this: the land for utility scale can be consumed
and then developers move on to larger roofs (applicable more in Europe); incentives for
large scale solar are diminished, as the market takes off, while incentives remain for roof­
tops; perception of success of ground mounted projects leads to more acceptance and
more consumers looking for their own solar; and so on. What is clear is that land con­
straints certainly lead to rooftop markets, with small countries, such as Slovakia, Ireland,
Belgium, and Switzerland having almost 100% of their solar on roofs.
In Europe, we can observe that where retroactive measures have been brought into
play in a solar market, the expressed trend of moving from ground mounted solar into
rooftops does not happen. Romania, Bulgaria and Spain remain markets with less than
20% of their deployed solar on roofs, against the market trend of close to 70% of solar being
on European roofs [1]. This certainly suggests that governments that seek to slow down
or kill fledgling solar markets can do so with regressive and destructive policies, designed
purely to limit solar power. This highlights once again the crucial role that regulation plays
in solar deployment, as the economics of solar in Spain suggest that for much of Southern
Spain solar is already at grid parity [21]. Therefore, if economics alone were to drive solar,
you would expect much more than the 5 GW that have been installed to date in Spain.
Returning to the segmentation, Europe has become a rooftop market and most com­
mentators expect this to continue [1]. The fact remains that in markets like the united
Kingdom, which have experienced a large boom in ground mounted systems, the rooftop
market remains wide open for exploitation. It is reckoned that a city, such as london, has