Case study
ENERGY
Princess Alexandra Hospital - Harlow, Solar Panels
The roof of the Princess Alexandra
Hospital in Harlow, Essex now has
what is believed to be the largest
array of solar panels currently in
the NHS. The hospital which serves
a quarter of a million patients, over
five sites has been working on
projects exploring the potential to
save money and C0 2 since 2006.
Bill Dickson, the Energy Manager hopes
to build on the learning experience so
far and carry on expanding renewable
energy generation in the coming
years.
The project was driven by a need to
reduce energy spend which was set
to rise from £1 million to £1.5 million
due to rising national energy costs. A
grant of nearly £400,000 was secured
from the Department of Health’s
Energy Fund in 2007 and work started
installing two new energy efficient
boilers and solar panels in summer
2008.
The savings achieved by the solar panels and
new efficient boilers equate to a reduction of
8,000 m 3 of gas and 16 tonnes CO2 per year.
When we refer to solar panels it is
important to know that there are two types;
Photovoltaic panels which capture the
suns energy and convert it into electricity
and Solar Thermal Collectors, which are
described in this case study. Solar Thermal
Collectors use the suns energy to heat
glycol which passes through a coil.
“It has been immensely frustrating over the last year to see many of our wider
energy saving efforts wiped out by the rises we have seen in gas, energy and oil. It
has been particularly pleasing, therefore, to be commissioning the solar thermal
energy system, which will hopefully bring us significant energy savings once fully
operational, at a time where cost saving is becoming ever important”.
Bill Dickson, Energy Manager
The solar panels use solar radiation and sunlight, so
they work constantly, only slowing in output on really
dull days when traditional energy sources are used to
run or supplement the boilers. The solar panels heat up
the sites water prior to it reaching the boilers therefore
the boilers have to do significantly less work.
This is a project that could be replicated
on any south facing NHS building that
has a high demand for hot water. The
payback time for the project is between
ten and twelve years, however this may
become considerably less if energy
prices continue to rise.
“We are keen that other trusts, who may
be scratching their heads about how to
cut their energy costs at a time when we
are all under financial pressure, see what
we’ve achieved and consider how they
might follow suit”
For more information contact Bill DicksonEnergy Manager. [email protected]
This has resulted in a 50% reduction in the number of
times the boilers have to fire up to heat the water to the
safety levels specified in HTM 04-01, this sets the guidelines for the control of Legionella, hygiene, ‘safe’ hot,
cold and drinking water systems. At optimum operation levels, 40-50% of the buildings hot water requirements are met by the solar panels output. Bill Dickson
also commented that the solar panels are low maintenance, which is a real benefit as maintenance bills are
being constantly squeezed.
NHS Sustainable Development Unit
Victoria House, Capital Park
Fulbourn, Cambridge CB21 5XB
Tel: 01223 597 792
Fax: 01223 597 712
Web: www.sdu.nhs.uk
The NHS Sustainable Development Unit
develops organisations, people,
tools, policy, and research
to help the NHS in England fulfil its
potential as a leading sustainable
and low carbon organisation.