Legislation to foment the use of renewable energies and solar thermal energy in building construction: The case of Spain - Solar Energy Sciences and Engineering Applications - page 659

speaking, should not exceed 15%. In building projects, it is obligatory to include a
report that states the calculation method. It should specify, at least on a monthly basis,
the daily mean values of the energy demand and the solar contribution. The calculation
method should include the annual overall capabilities defined by the thermal energy
demand, the thermal solar energy contribution, the annual and monthly solar fractions,
and the annual mean yield.
It is necessary to ascertain whether there is any month of the year in which the
energy theoretically produced by the solar installation exceeds the demand correspond-
ing to the actual building occupancy or to any other period of time in which overheating
conditions might occur. In such cases, measures should be taken to protect the instal-
lation. The performance of the solar collector, independently of the application and
technology used, should always be equal to or greater than 40%. In addition, the
mean performance of the installation during its period of operation should be greater
than 20%.
In order to assure system operation and prolong the useful life of the installa-
tion, a monitoring plan and a programme of preventive maintenance are implemented.
The monitoring plan involves actions to guarantee that the operational values of the
installation remain within normal range and thus guarantee its smooth operation.
This simple plan includes, among other things, the visual inspection of installation
components and maintaining the collectors in a clean condition.
The maintenance programme involves a series of actions to ensure optimal oper-
ating conditions, capabilities, protection and the general durability of the installation.
Such maintenance should be performed by trained personnel, and includes all repairs
and replacement of consumable units as well as parts that have suffered deterioration
during the useful life of the system.
20.6 MEASURES TO FOMENTTHE USE OF RENEWABLE
ENERGIES: GOVERNMENT INCENTIVES
The EU (e.g. Regulation (EC) No 397/2009), (EP&C, 2009b) as well as the govern-
ments of EU member states have provided incentives for initiatives that improve energy
efficiency and/or the use of renewable energies in building construction. These incen-
tives are often tax-related (i.e. tax exemptions, deductions or refunds) or are in the
form of investment aids and project loans at low interest rates. The beneficiaries of
this financial aid can be either the users of the installations, who can use it to purchase
solar equipment, or the companies that develop and manufacture renewable energy
systems 27 .
For example, for the production of electrical power with photovoltaic solar instal-
lations, the Spanish government has included these installations in a special regime.
This regime, as specified in the Ley del Sector Eléctrico (1997) [Electrical Sector Regime
Law], was conceived to foment power generation by energy sources whose special char-
acteristics deserve higher financial returns than they would ordinarily obtain. Special
regime energy sources receive higher remuneration than those belonging to the ordinary
regime through a system of feed-in tariffs and premium payments.
27 Businesses that market, install, service and sell this equipment or the energy produced by it.