Going about my daily business, I have had many meetings with large installers of renewable energy systems. At one such meeting, where I was hoping to fuel enthusiasm for a district heating system, I was told: “Our local housing association will not entertain heat pump technology as valid option.”
Further investigation indicates that this opinion is not isolated, having been influenced by reports of poor operational economics over a number of sites and, not least, the often-negative content of online heat pump forums.
Quantification of performance is not easy, as very few heat pumps actually display their operating-economics in a manner that is meaningful to the user, which means that any criticism of this technology is usually based upon perception rather than fact.
I have banged the drum on the merits of heat metering on many occasions in my column, but the importance of accurate monitoring cannot be over emphasised.
Generally, heat pump systems have no easy-to-read visual indication to display their operational economics, and the adverse effect of system faults, component mismatches or other defects, can remain without diagnosis for long periods of time, causing costly negative impact for the bill payer.
Repeatedly, I find a number of prominent factors contributing to consumer complaints regarding heat pump installations:
1) Over enthusiastic sales force overstating the economics of operation
2) Heat pump system efficiencies adversely affected by bivalent energy
3)Heat pump undersized for the application
4) Insufficient water flow rate
The effect of bad news travelling fast puts growth of this industry under constant pressure.
The bad news influence is particularly evident in a number of housing associations where heat pumps have failed to deliver the anticipated economic goals. Adverse results are often made more visible by tenants who are on a low income and thus, more vulnerable to unexpected high heating bills.
Before this valuable technology is completely discredited, we need to create remedies quickly. If problems of this nature are unaddressed, I fear the market, and perhaps even the UK government, will abandon support for this useful technology.
In the UK we have the availability of natural gas at very attractive prices, and the network of supply is significantly more comprehensive than our European neighbours.
Because of this, heat pumps operating in UK, are tasked with meeting more stringent economic goals, created by our superior gas supply network and reinforced by keen prices.
Heating requirements vary significantly with lifestyle and the limitations of heat pump technology should be understood before installing a heat pump.
For off-gas districts a well-balanced heat pump installation generally represents good value for money, and further enhanced by the RHI payment, although operational limitations must be understood.
There are many more factors to consider, over and above the points I have raised here and the principles of low carbon energy delivery through heat pump technology are completely sound.
In our evolving world of renewable energy, the common denominator is of course electricity, as evident from the output of wind, solar, hydro and tidal.
A heat pump represents the most economical of technologies available in converting electrical energy into thermal energy, and represents the only renewable energy source available completely on demand.