Power saving for home patients
As haemodialysis (HD) is a power-hungry process, and as electricity costs rise, home HD patients are inevitably faced with escalating electricity costs – the extent of which are largely determined by the dialysis regimen.
For home haemodialysis patients, longer and more frequent dialysis regimens – while likely beneficial to clinical outcome and general health and well-being –also demand a higher electricity use and generate a proportionately larger power bill.
Home peritoneal dialysis (PD) patients, if using a peritoneal dialysate cycler system (e.g. a Baxter Home Choice 2™ or a Fresenius Liberty™ cycler), will also face a larger power bill, which, though far more ‘modest’, is nevertheless an additive cost.
Re-imbursement for utility costs (water and power) in now available in some jurisdictions – especially in Australia. But even in Australia, reimbursements vary, state by state.
The following map – annually updated by the Home Network – shows the 2017 utility reimbursements that apply in the various Australian states.
As part of a study to document the carbon footprint of an Australian suburban dialysis service, the annual power requirements of a standard single-pass haemodialysis system (3 x 4 – 4.5 hr dialysis treatments/week) plus the power used by the RO system for those treatments, was found to be ~½ the weekly power requirement of an average Australian 4-person home in 2012.
For the home patient, where both dialysis duration and dialysis frequency are commonly significantly greater, power consumption would be expected to be even higher.
While this has not yet been measured or reported from Australia, a UK study has shown exactly this where power consumption depended on the equipment and prescription used for home care. This study showed that the carbon footprint left by the NxStage system (not used widely in Australia but a common home system in the US and, to a lesser extent, the UK), is only ~25% of the power used by a single pass system + RO.
Home patients should critically seek to lower their overall power usage. There are two primary steps to consider:
- Follow the usual and well-publicised standard steps to reduce excess household power use.
- Consider renewable power-assisted options… e.g. solar or wind power.
Alternative power-assisted home HD
There are now some limited reports surrounding the use of solar panels in augmenting the power usage of home haemodialysis. Data obtained from a Barwon Health solar-assisted HD pilot study showed that a solar array that cost AUD$3,400 in 2011 was sufficient to provide all power needs for an alternate nightly 8-9 hour home HD regimen. This data was reported in abstract format at the 2012 EDTA meeting in Paris (1).
Clearly, these patients were dialysing at night and, as such, could not directly ‘power’ their dialysis system from their solar energy source in real time. However, the installed solar system was matched to contribute a weekly daytime power equivalent that balanced the weekly nocturnal power draw of the dialysis machine and RO.
As night-time power costs (rates) are commonly lower than daytime rates, this may be a financially viable option.
A Geelong home haemodialysis patient, at his own expense, installed a solar array sufficient to provide all home HD power needs ($3,500). He reports that he now pays up to 80% less for his entire household power expenses. Because of this, several home HD patients from this same home dialysis service have now embraced the solar option. However, return on investment is subject to pricing variability.
The Victorian Environmental Special Interest Group, a working group of the Victorian Renal Clinical Network, has developed a fact sheet for patients on ‘Going Solar with Dialysis’. This provides useful information on the benefits and costs of solar, and how patients might go about finding the solar system that best suits their needs.
Services should educate patients about home solar-assisted HD, and support them, depending upon the solar insolation data for their region and the local cost profiles for solar generation.
Calculating home haemodialysis solar power requirements
Solar panel installation companies should be able to assist in working out the solar requirements based on electricity bills and meter data. They should also be able to advise on the appropriate sized unit. Obtain at least two quotes to allow comparisons between recommendations and prices.
To calculate …
- Use a standard electrical industry power-meter to measure the hourly power drawn by the dialysis equipment – both dialysis machine and RO system
- Do several measurements on several machine/RO pairs and average the data.
- Determine the daily average solar insolation at the latitude and longitude of your home using the following method:
- Go to: www.wunderground.com/calculators/solar.html enter your city (eg: Geelong) and country (Australia).
- Check the ‘Give raw insolation data’ box.
- Scroll down to ‘Submit’ and click.
- A graph will appear, showing the raw monthly insolation data for your location (eg: Geelong) in kWh/m2/day.
- The average kWh/m2/day is calculated (Geelong = 6 kWh/m2/day).
- Thus, each m2 of panel will generate ~6 kWh/day power.
- Check your local solar power supplier for available products, and then select one of these from the many listed solar arrays modelled at this Internet site.
- The ‘generative efficiency’ will be automatically determined.
- If the chosen/preferred array is unlisted, (eg: the array used for the Barwon Health trial was a Conergy 175), the efficiency rating for that array can be supplied by the chosen manufacturer.
- Finally, a predicted potential cost/benefit outcome can be calculated, based on power requirements, array size, and installation cost.
Green electricity providers for home dialysis patients.
If solar power isn’t an option for your home, consider purchasing electricity from a ‘green’ provider. Shop around. You might be surprised at both the differences in price, and the % of power your company offers from “green” power sources. By choosing a ‘green’ retailer that generates its energy from renewable sources rather than fossil fuels, you will not only be reducing the environmental impact of your energy usage, but also supporting the renewable energy industry in Australia and sending a signal to Australian energy companies that you want them to get serious about tackling climate change.
- Greenpeace has compiled a Green Electricity Guide which provides an independent, unbiased ranking of the environmental performance of all retailers selling electricity to Australian households.
- Choice has also independently rated 23 energy retailers on their green credentials.
- The Australian Government site EnergyMadeEasy allows comparison of the cost of different electricity offers from energy retailers in Victoria. Similar resources are available in other states also.
- Agar JWM*, Perkins A, Simmonds RE, Tjipto A. An affordable model for solar-assisted home haemodialysis. (Abstract only). Nephrol. Dial. Transpl. 2012: Proceedings: European Dialysis and Transplant Assoc. / European Renal Assoc.