Pump element is overlooked
Mitch Holmes of Grundfos' Water Group argues the environmental impact of the enhanced capital allowance initiative is compromised by a failure to look into hydraulic efficiency
There is still a large amount of confusion over the whole area of enhanced
capital allowance (ECA) and the consequences of having just motors, without
pumps or pumping systems on the energy technology product list. Although plenty
has been written on the subject, very little forms a cohesive picture which
can be readily understood.
At the Earth Summit in Rio, 1992, in excess of 150 countries agreed to limit
man-made emissions of green house gasses (GHG). This decision formed part of
the global ambition to stop the atmosphere from overheating. By the 1997 Kyoto
Summit, it was agreed that developed countries would aim to reduce GHG emissions
by a further 5.2% between 2008-2012. The EU committed itself to an 8% reduction
in emissions, with the UK contribution being agreed at 12%.
Following this, a government initiative was introduced to drive down GHG emissions
generated from electricity production. The Climate Change Levy (CCL) has been
levied on business users to encourage the reduction of energy consumption. The
CCL is applied at different rates, depending on the energy content of the different
sources. For instance:
- Liquid petroleum gas (LPG) – 0.07 p/kW/h,
- gas, coal, lignite and coke – 0.15 p/kW/h,
- electricity – 0.43 p/kW/h.
Electricity attracts a higher tax rate as a considerable proportion of fossil
fuel energy is lost in combustion, transmission and distribution. Petrol, diesel,
road fuel gases, mineral oils, waste and other renewable energy sources are
not taxable commodities under this scheme.
To encourage companies to switch to more efficient and environmentally friendly
options, an incentive was introduced in the 2001 budget. This took the form
of a claimable allowance for businesses that invest in energy efficient technologies
including boilers, refrigeration, combined heat and power, lighting, pipework
insulation, thermal screens and motors and drives.
The ECA helps to lessen the impact of the CCL’s affect on fuel bills by allowing
companies to set 100% of the cost of approved energy saving equipment against
corporation tax in the year of acquisition. Instead of writing down capital
equipment over a period of years, the ECA provides a cash-flow advantage which
helps to offset the capital investment cost.
How to qualify
The energy technologies list includes both variable speed and fixed speed high
efficiency motors with efficiencies typically between 83%-95%. When these motors
are fitted onto pumps it is possible to claim the ECA on the percentage of the
price of the motor.
Additionally companies can also claim ECA on costs directly associated with
the provision of the product, i.e. transportation, installation, modifications
to existing plant and machinery and commissioning. Professional fees also qualify
if they are directly attributable to the acquisition and installation. Finally,
the allowance can be claimed where costs have been incurred as a result of altering
an existing building, incidental to the installation of qualifying plant and
Defeating the object
With motor efficiency rising as high as 95% there is little scope for improvement
in this area, however, considering 20% of the world’s electricity bill is spent
on powering pumps, it is vital the bigger picture is taken into account. It
is possible to claim ECA on a high efficiency motor, irrespective of the efficiency
of the pump it is attached to. It is not unusual to have pumps with an efficiency
point as low as 40%. Therefore, consider the possible impact on electricity
consumption if the same benefits were applied to hydraulic efficiency.
Grundfos has identified a number of ways that hydraulic efficiency could be
improved. Enhanced impeller design, for example, can result in a more streamlined
flow in the impeller and reduced eddy flow and friction loss. Since such small
margins of error are involved, Grundfos has developed highly specialised laser-welding
technology, which operates at, so far, incomparable levels of accuracy. With
this technology, the impeller design and construction are fine-tuned to the
point of theoretical perfection. This alone can contribute to increasing efficiency
by up to 4%.
Another method is to minimise internal leakages caused by the pressure differentials
within the pump. Tests and calculations have shown that an impeller seal clearance
gap of 0.1mm, between the impeller and the chamber in a pump, results in a 5%
drop in efficiency. To reduce internal leakage to a minimum, it is now possible
to use a floating seal ring between chambers, providing a virtually perfect
seal. If a 10% increase in pump efficiency is achieved smaller motors can often
be used to power the pump at any given duty point. A smaller motor represents
a reduction in both capital investment and running costs.
With these technological advances now available, it is possible to achieve
hydraulic efficiencies in excess of 80%. When this factor is combined with the
accessibility of high efficiency motors, the result could be a major contributor
in reducing GHG emissions and help the UK move towards achieving its environmental
Every year 900,000 multistage pumps are installed around the world, if they
were all as efficient as the Grundfos CR range, the electricity saving in the
first year would be 1.45tWh. Put into context, this equates to 590,000 tonnes
of coal. If this was then used to generate electricity, emissions would be in
the region of 1.43M tonnes of carbon.
The way forward
When purchasing white appliances, there are energy rating labels giving an easily
identifiable guide to the efficiency of the overall unit. In the case of a washing
machine this would include the motor and washing mechanics as one. Could this
be the way forward within the pump industry? Perhaps classifying pumps as one
complete unit with a combined efficiency, grading and labelling would help to
alleviate some of the confusion that currently exists.
Building on this, the combined pump unit should be included on the energy technologies
product list, ensuring the pump industries continued contribution to the environment
and Kyoto Protocol.
There are many financial, ethical, environmental and practical reasons to look
closely at this topic. The environmental abuse of the last century was mainly
a result of ignorance. However, the advances being made by manufacturers like
Grundfos Pumps will prove valuable when specifiers design products that can
make a real difference.
© Faversham House Ltd 2023 edie news articles may be copied or forwarded for individual use only. No other reproduction or distribution is permitted without prior written consent.