I think there's a substantial amount of discussion about the Stirling Cycle on the Web but I've yet to see knowledgeable independent reviews
which think it's time has come. One reason is that, along with a lack of track record
, there's little supporting infrastructure - e.g. you may not have heard back from the NZ outfit simply because it's a small biz and they are juggling lots of balls right now. When you reflect on the fact a liveaboad cruising boat needs bulletproof systems, new technology promoted by limited resources and without a long track record
just doesn't seem to conceptually fit. This doesn't mean it won't...eventually...but then again, maybe it's like other novel, innovative ideas that just can't migrate to mature systems of practical value. The question is whether that's a gamble you want to take...
I'm also wondering about the nitty-gritty of the ratonale, at least insofar as the marketing
poop offers it up:
1. Heating: current
diesel-fired heating systems come in two versions - water
heating and air heating. The view of water
heating is that it's great as a long-term (e.g. liveaboard) application as the piping is typically run around the boat beneath the cabin sole
or nearly so, and so you get not just warm air via the heating registers but a warm thermal mass. However, the downsides are that it generates huge amounts of condensation
beneath the cabin sole
, takes quite a while to build up the thermal mass, the unit runs for longer periods of time (which requires such a system to offer this longevity) and of course fuel burn consequently goes up. So far, water-heating models, deployed in about 50% of the boats here in N Europe
, fail much more often than the air-heating systems, principally because the water heating methods were originally built to heat up commercial
truck engines before they were started, and so weren't intended for this kind of long-term use. These issues aside, it leaves me wondering if you'd want to live with a heat-producing system that's burning most of a gallon of fuel each hour, or even a minority of a gallon. E.g. I compare this with a bulkhead-mounted diesel/kero heater we use on WHOOSH which runs for perhaps 10 hours on approx. .75 gals of kerosene. It doesn't do the same wide-spread, even heating of a distributed system, but we use a small fan to push the warm air around the main cabin
and in 45+F temps, it makes things very pleasant after perhaps 20 mins of heating-up time. The whole Canadian system (from Force 10) costs perhaps $500 and is simple to maintain. For sustained use in lower temps (e.g. living aboard
in Vancouver marina), this wouldn't be adequate but you then have other simple/inexpensive options like multiple kinds of electric
heat. If you hope to be independent of shorepower AND live in sustained, near-freezing temps, your heat source has to be absolutely beyond question...and a new technology from a new company of limited resources doesn't conceptually fit, as discussed above. (As e.g. when compared with a DC-powered diesel-fired heating system that's been around for decades). So the rationale escapes me when I dig into the detail...
2. DC power generation: They pitch
this product as making AC power available for AC appliances
via an inverter
but on a more efficient and presumably more cost effective basis than an AC generator. My question is: How did we get to needing the AC appliances
in the first place? There are a lot of cruising boats with AC power generation onboard, so I realize my perspective varies from the approach of some cruising folks...but I think it's fair to ask to what extent you want to set yourself up for dependence on AC appliances. And to that extent, is an AC power generation source your best answer? You will notice that on cruising boats with big systems (e.g. a beefy reefer compressor), they will sometimes opt for a mixed 24V and 12V DC system, which allows them to power big motors more efficiently using DC and/or they find other ways to meet their needs (e.g. heating water in some non-AC dependent fashion). It would seem that the more one can meet his/her needs via DC equipment
, then the more that solar
DC sources can be relied on, at less cost and with less fuel dependence, with less complexity of systems, and without the inevitable efficiency losses one faces when moving between DC and AC or vice versa. And above the trees and to consider the forest for just a moment, doesn't a long-term cruising goal suggest that the simplier the systems, the more redundant they are, and the more easily systems can be fixed or replaced, then the happier one would be? As a reverse illustration, there is an older Amel across from us right now that uses 5 DC motors in normal operation (3 furling
, thruster), has a big AC fridge, and is dependent exclusively on an autopilot
for self-steering (a critical system since it's a husband/wife crew). All of this boils down to total dependence when offshore
on their generator, something they appear to be content with...but of course the question is whether this makes sense for the next person.
It would be great if this system we're discussing were taken aboard a cruising boat and then the boat sailed perhaps several years and many thousands of miles. The feedback would be invaluable, and yet it would be just one data point and we'd wish for a hundred more. This is a good example of why technology is slow to enter the cruising boat marketplace. It isn't just that we're stuffy traditionalists; there's a lot to consider between the promise of the core
technology and what it's like to live with these things and, at times, critically need to rely on them.