Environmental Engineering Reference
In-Depth Information
5.5 Economics
Photovoltaics is already an economically competitive technology in several
niche applications. Small applications are often supplied with small batteries or
button cells. Compared to household electricity prices of around 20cents/kWh
in Germany, for example, the costs with photovoltaics can quickly explode to
several hundred euros per kWh. It takes about 280 mignon cells to store one kilowatt
hour using high-quality alkaline manganese batteries. Now, no one would ever
think about buying 280 mignon cells to run a washing machine just once. However,
with small applications we often tend to be willing to pay whatever it costs to
buy batteries. It is often the infrequent use of these small applications that even
makes using electricity affordable. Photovoltaics can compete with this type of
high energy cost even under the cloudiest conditions. It is often an economic alter-
native even to large battery systems. However, photovoltaics will have to relinquish
its niche role if it is to become effective in protecting the climate. This will only
happen if it becomes a grid-connected system and replaces conventional power
plants.
5.5.1 What Does It Cost?
A sensible minimum quantity of power for a grid-connected photovoltaic system
is 1 kilowatt peak (kW p ). There is no upper limit; this depends only on the area
available and the amount of money available. Fortunately, the prices of photovoltaic
systems are dropping so much that they are out of date even before they are
printed. This makes it diffi cult for any topic to provide a current guideline to prices.
In 2008 it took an investment of around 4000 euros for a completely installed 1-kW p
system. The price of the photovoltaic module itself only constitutes a part of
the total system price. A good 60% of the investment goes towards the PV modules,
while the rest is spent on inverters, mounting materials, the actual mounting and
planning.
Whereas the lion's share of the cost with photovoltaic systems is in the installation,
the payoff then comes through the electricity that is generated. The reimbursement
is usually per kWh. The operating costs of photovoltaic systems are comparatively
low. An estimated 2 to 3% of the investment costs each year will be spent on running
costs, such as insurance, possible leasing, meter rental and reserves for repairs. The
modules can normally be used for 20 to 30 years. Inverters, on the other hand,
usually wear out earlier. Repairs and replacement parts should be included in the
calculations at the outset.
Another factor that has a major effect on production costs is the return. Very
few sensible people will invest their own capital in a photovoltaic system in the
hope of at best receiving their invested capital back again over the lifetime of
the system. An investment should at least be comparable with a savings account
to make it attractive to large numbers of people. Even then a certain amount of
idealism is required, because the risks associated with photovoltaic systems are
 
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