CARBON AND ENERGY SAVING 1
Natural Gas
Electricity Grid
Battery Storage
PV 2 3
Hydrogen Grid
Hydrogen CHP
Chilled Water
LTHW Network
Fuel Cell CHP
Thermal Store
Heat Pump
Hybrid Heat Pump
Gas CHP
Absorption Chiller
Intermediate to short term Low impact to site infrastructure
n Existing heat from gas boilers n Steam still used
Steam Boiler
LTHW Low NOx Boiler
n Partial de-steaming with efficient use of gas CHP
LTHW Gas Boiler
Hybrid Energy Boiler
n Technology available now n Good financial savings n High NPV n Low carbon savings
Figure 1: Three stages to net zero carbon.
these costs would no doubt be passed on to the consumer. By the same token, the costs for remaining with fossil fuels for heating will also become more expensive as a result of increasing levels of taxation applied in the short to medium term. The UK Government has already committed to increase the Climate Change Levy (CCL) on natural gas at a faster rate compared with electricity in the next five years.
Context for investment in decarbonising the NHS estate It seems likely that NHS Trusts will be operating their estates in the context that significant gas decarbonisation in the next 10 to 15 years is likely to be small, compared with the increasing levels of electricity decarbonisation possible over the same period. Therefore, any investment in energy efficiency that displaces grid electricity is likely to result in good levels of financial savings continuing, but diminishing impact to a Trust’s carbon footprint per kWh as the national grid ‘greens’. On the other hand, investment in energy efficiency that
42 Health Estate Journal June 2020
displaces each kWh of natural gas (and other fossil fuels) will show more resilient carbon footprint savings, and a lower, but improving, level of financial saving by comparison.
The realisation of this should be guiding the strategy for ensuring that the NHS estate does not get left behind on the road to decarbonisation. How, though, does it influence the principal approaches to be prioritised, set against backlog on plant and infrastructure that in many cases was designed and installed many decades ago, and will struggle to evolve into the solutions needed to deliver increasing levels of decarbonisation, and, ultimately, net zero carbon?
A degree of uncertainty It is difficult to show attractive financial viability for implementing big solutions while gas prices remain relatively low. Also, there is a degree of uncertainty about the future, in terms of what is going to be the best replacement technology to incorporate, and whether gas remains viable in the medium to long term, or whether it is even possible to switch heat
demand from fossil fuel over to low carbon electricity without incurring hugely prohibitive capital and running costs.
A staged approach
It is very unlikely that it will be technically or financially practical to jump from where we are now, straight into a net zero position. There is a likely route map that must be established, so that investment decisions on future plans for the estate can be accommodated, and that infrastructure is developed along lines that will not annex off a Trust from adopting future low carbon solutions, or lead to ‘dead ends’, where the ability to adapt becomes completely unviable, or totally cost-prohibitive. The staged approach needs to start addressing fundamental building blocks for each site’s energy infrastructure, including that which can be addressed now, and how this will then be progressively built upon in the coming years, taking advantage of the progression of technology. The following approach is outlined, based upon a typical acute hospital (see Fig. 1).
Short to medium term
Medium-high impact to site infrastructure n No steam heating n Efficient gas CHP (heat led) n LTHW heat networks n Technology available now
n Higher cap-ex, lower financial savings
n Lower NPV n Higher carbon savings, lower NOx
Medium to long term High impact to site infrastructure
n Gas engine CHP retired, or converted to H2
n Heating by electric heat pumps, hydrogen fuel cells, hydrogen fuelled boilers
n Technology not widely adopted or available yet
n Highest carbon savings, zero NOx n Low carbon savings
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