B UILDING & M ANAGEMENT
E LECTRICITY IN HOSPITALS : SOLUTIONS BASED ON ECONOMIES OF SCALE
V OLUME 3 I SSUE 3 S EPTEMBER - D ECEMBER 2019 G. S ÁNCHEZ -B ARROSO , M. G ÓMEZ -C HAPARRO , M. J. C ARRETERO -A YUSO AND J. G ARCÍA -S ANZ -C ALCEDO (2019). B UILDING & M ANAGEMENT , 3(3): 12-16
exploitation.
be paid regardless power delivery, and a variable part
(energy price), that will change according to consumption. In
this case, the price to be paid for the hospital will be given by
the Equation (1):
On the electricity market side, the risk is related to the
volatility of the daily energy price and the generation profile
according to technologies. The price of energy is determined
by the result of the daily matching that takes place in the
daily and intraday electricity market, which, in turn, is mainly
conditioned by weather conditions and the price of the fuels
used in generation. The generator profile differs according to
the technologies used in generation, being a problem the
randomness of those renewable technologies (hydraulic and
wind) in comparison with the combined cycle plants (clearly
defined).
(1)
Where: P is the price of bill in EUR, F is the fixed part price in
EUR, Q is amount of energy consumed in MWh, and c is
associated price to the indexed market.
Figure 1 shows the temporal evolution of the cost incurred by
the hospital complex throughout the year.
The established procedure begins with the consumer, in this
case the hospital, with the intention of achieving an increase in
the energy efficiency of its system. The way to reach this
improvement is usually by investing in new, more efficient
technology. However, another path that led to such an end
was followed in this work. An energy management from the
point of view of contracting electricity supply was proposed.
In this way, the risk of the investment and the operating cost of
the building is reduced. The result is a consequent optimization
of energy consumption that allows financing technological
improvements.
The monetary savings resulting from the elaboration of energy
efficiency and savings strategies, or from the optimization of
the electricity contract, were not treated as a benefit but as
an economic source to finance investments in renewable
technologies or to improve energy efficiency, as results of
producing savings in operating costs.
Consequently, energy efficiency was understood not only from
the point of view of minimising consumption, but also from the
economic point of view, with efficiency being understood as
the savings generated by the correct management and
contracting of the electricity supply.
3. R ESULTS AND DISCUSSION
Figure 1. Evolution of the cost of energy throughout the year according to fixed price (left) or indexed
price (right).
The first option that is shuffled is through a marketer. The
seller is an intermediary agent between the electricity market
and the end user. They buy energy as wholesalers and sell it
to the consumer by billing each customer individually. This
option allows two types of contract: fixed price or indexed
price.
The second option available to large consumers is coverage.
This option is proposed in order to reduce the influence of the
daily price volatility. For this purpose, an energy exchange
price is proposed for a certain period of time. At the end of
this period, the differences between the agreed price and the
settlement price are calculated. This is the most complex option
and can be carried out through a swap or through a power
purchase agreement (PPA).
On the first place, the fixed price modality transfers a large
part of the risk to the marketer since the price is agreed with
the client. Traders include a risk premium in the agreed price
depending on the volatility of the energy price. This modality
implies that the hospital would pay the same price for the
electricity supply regardless of its consumption. On the second
place, in the indexed price option, the risk is transferred to the
client. In this case, the energy price is in line with the market
price. This price includes a set part (transport costs, energy
and power tolls and applicable taxes, included), which must
The energy cost acquired in the market results from the sum of
the product of the energy acquired by the hour and its price
fixed in the daily market (DMP), which is expressed in the
Equation (2):
(2)
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