Election Win in Western Australia for Diesel Generators

Western Australians voted in a Labor government on the 11th of March, 2017.

Here are a few words on how sensible people might prepare for the next 4 years under Labor.

The Australian Labor Party (ABC 😉 ) has a penchant for “renewables”, regardless of the fundamental limits that make it inappropriate for the energy needs of modern, technological society. The South Australian experiment was destined to fail from the outset so the collapse of their grid in September last year was no surprise to anybody with something of an understanding of the fundamental limits of renewables and what it takes to provide reliable electrical power to consumers.

(Australian Liberal parties seem to have lacked the technological competence to provide it with the confident footing to rigorously oppose the insanity of plunging deeper into renewables.)

There are many options that can confuse the prospective buyer of a generator.

First of all; the generators are rated in kVA; kilovolt-amperes; which for a resistive load like a bar heater of electric kettle, is equivalent to kilowatts (kW). It gets a bit messy with inductive loads like electric motors or capacitve ones such as switchmode power supplies in computers, TV’s, etc. and LED lamps. But for all reasonable appliances and electrical equipment, it’s near enough for sheep stations.

To determine the rating, you need to survey your appliances and find out how much current/power they use; and then work out what’s reasonable for you to be using at the same time; when there’s a prolonged power outage. The secret to finding out how much electrical power an appliance consumes is to read the “nameplate”; which may be a shiny sticker near the power inlet or often molded-in text on plug-packs.

A battery and inverter might help to keep the house alive in the event of power failure. Tesla’s PowerWail™ will have less than 7kWh of typical reserve which won’t keep the average household ticking over for even 12 hours; but its inverter, which converts battery DC into household AC, is too wimpy to run even a single electric kettle!

2.4kVA petrol inverter generator (for illustration only)

It is tempting to spend as little as possible on the first “special” generator on offer. Should you only want to be able to run the 2.4kW electric kettle (or less), then a 2.4kVA inverter petrol generator may be a good fit. Prices for cheapies are well under $1000. Watch out for the noise level and you ought to be able to find one rated at below 60dBA at 7 metres. I’ve highlighted the inverter bit because that bit of electronic “magic” lets the generator produce “clean” 50Hz power, regardless of motor speed; allowing the generator to slow the motor down when not much power is needed. This makes the small generators much more efficient than what they would be otherwise.

If you want to be able to brew a cuppa while the washing machine

11kVA diesel 3-phase generator (for illustration only)

is running, then 5kVA is about the minimum generator requirement. That’s diesel-generator territory. And anything less than about 8kVA will likely be air-cooled so intrinsically more noisy. Even the “silenced” ones come in at 70dBA at 7 metres; which is quite loud (twice as loud as the previously-mentioned petrol unit) and if not in a “shed”, would be annoying to neighbours at night. Prices for them start around $1200; noting that those are rated as backup generators and not for continuous (prime/primary) use. So if you run it continuously; expect it to break down.

The low end diesel generators are NOT inverter units. Prices for them started around $4000, last time I checked. The result is that the power from them is a bit wobbly in terms of frequency and voltage so I would advise running expensive equipment off them until you’ve “seen” that they’re unlikely to damage the appliance.

In terms of fuel; the small petrol unit will have a tank with enough fuel for a few hours; usually less than 4 hours at rated load (less than 10kWh electrical power consumption). The bigger diesel units will have a tank capacity for about 12 hours at rated load (i.e. providing about 60kWh)

The diesel generator could, in theory, be safely refuelled while generating whereas it’s never a good idea to top up the fuel tank feeding a running petrol engine. i.e. the diesel can keep generating non-stop as long as you have a supply of diesel fuel.

As for the fuel itself; I am unsure of the arrangement for buying it without paying fuel excise (road tax). This will vary from jurisdiction to jurisdiction as well as the fuel merchants. If you’re a farmer, you probably know the drill.

Diesel generators should have about half the fuel consumption of petrol generators. Specific fuel consumption of the engines is typically less than 200 g/kWh for diesel and around 340 g/kWh for petrol. Diesel is more dense than petrol so those figures translate to 0.24 l/kWh for diesel and 0.49 l/kWh for petrol.

If your household consumes 20kWh of electrical power per day, then you need at least 10 litres of petrol or 5 litres of diesel per day for energy “independence”. The relative volatility of the fuels must be considered if you’re going to keep stock on hand. If there’s a regional blackout for days, then few service stations will have operating bowsers, as they don’t usually have generators hooked up to run the pumps when there’s a power failure.

It helps to run any internal combustion engine under significant load; near maximum load for petrol, but anywhere from 30% to around 80% on diesels; for maximum efficiency and the best (lowest) fuel consumption. Batteries and a capable inverter (3kW minimum; ideally with a peak greater than generator output) will help to provide power quietly for hours overnight and allow the generators to “cycle” mainly at efficient levels during the day; or to be set spinning when you’re about to use a lot more power than “average”.

Fuels don’t “keep” forever. Depending on storage; you should consider “cycling the fuel on an annual basis; running the generator for a while once every 3 months or so to confirm that it works and to consume part of our stock to be replenished (stored separately) ASAP, if not sooner. Earth Day might be an appropriate day to run the floodlights in the back yard for illumination until 11 p.m. to “cycle” some off-road diesel fuel.

If you want generator starts and connecting your appliances to it to be automagic; you need an ATS (Automatic Transfer Switch) that switches to standby power as soon as possible after the grid power fails. The ATS should be connected to house circuits that supply important stuff.

Cabling up the whole house is a major task at the mains input to the house; after the meter with isolation switches, signage and a large folio of paperwork. If you have something like battery backup and an “islanding” configuration from your PV inverter, then the transition can be “seamless”; with the generator kicking in as needed to top up the battery. The capital costs of such an integrated system is well into five figures; and operating costs around $1000 a year; even if you never “need” it.

I’d much rather that we had an electricity grid supply with five-nines reliability.

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