Flexible loads available in the NEM

The 2004 report http://www.energyrating.gov.au/library/pubs/200412-mepspools.pdf identifies that in Australia swimming pools and spas account for 3.3% of residential sector electricity. Pool pumps make a great “flexible” load; they are used for long periods of time even at times when it is likely that a demand side response is required, each pump uses a useful amount of energy, and nobody is going to mind too much if they are off for short periods of time.

Hot water is also a handy flexible load. Hot water uses around 30% of domestic energy consumption in most coutries including Australia. In Australia domestic energy is 28% of total energy (37% in the UK and USA). So hot water is around 10% of the grid in Australia and more overseas.

After a basic WW energy monitoring system is installed, it is a small step to include control over devices such as poolpumps and hot water (see last post).

In a deregulated environment, this flexible load can be (through contracts and technology) “mated” with flexible generators such as wind to create a stable grid and enable increased use of renewables.

The major market problemwith wind is that rapid fluctuations make it difficult to write contracts. However, these contracts become much more valuable when “backed off” with a demand side contract with access to 13% of the total grid!

Most pool pumps run on a timer. When installing control gear for poolpumps it should be possible to install a turbidity sensor that runs the pump for as long as it needs to run, and no longer, with potential energt, cost, and carbon savings.

In a WW system, verification of demand side reduction is automatic and accurate, as each load is constantly being monitored.

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Energy tip: Non-TOU metering and Solar Hot Water

Traditional metering (non time-of-use) often involves two meters.

Non-TOU meters bill at a stepped rate: 19.09c/kWh for the first chunk of 1750kWh per 91 days; 28.05c/kWh thereafter

The second meter bills the “Offpeak” circuit. This circuit is controlled by the energy company, charged at a lower rate, and used only for fixed installation of hot water and space heating appliances. There are two offpeak rates, and consumers can select which rate they are on.
- Offpeak 1 is currently 8.36 cents/kWh and available between 10pm and 6am
- Offpeak 2 is currently 12.1 cents/kWh and available for 16 hours per day, including 6 hours between 8pm and 7am and 4 hours between 7am and 5pm

The rate for solar hot water boost circuits are by default configured to Offpeak 2, which means they come on during the day. Mine used to come on an 8am, just when the sun starts to shine, thereby substantially negating the intent of the system, costing huge amounts of money, in return for year-round reliable hot water.

I tried changing rates, however Energy Australia will change tarrifs only once per year for free; more often costs $300. So even if Offpeak 1 was ok during the summer, I couldn’t switch to Offpeak 2 in the winter.

TOU metering, plus a timer, enables minimisation of energy used for solar hot water boost. “Offpeak” energy from a TOU meter is 8.8 c/kWh, about the same as non-TOU Offpeak (8.36). TOU “shoulder” rate is 14.96 cents, very slightly more than Offpeak 2 (12.1).

During summer, I set the timer to enable the solar boost circuit only during offpeak times. During Winter, I extend the timer to include some “shoulder” time.

Some understanding of when hot water is used, and the effect of the weather, can assist the planning process. Offpeak stops at 7am, too soon to heat water after morning showers. On a cold day, the timer could allow some heating into the shoulder period (as late as 2pm, or else after 8pm at night in time for evening showers).

While I can manage the timer manually, I can still run out of hot water if we have a few cold days in summer. This situation is recoverable quickly by bypassing the timer. But a better way is to fully automate using the WattWatchers network. This includes a weather forecast input, and some AI behavioural learning, and control over a relay instead of a timer.

Even without automation, a bit of intelligent experimenting and behavioural change can achieve significant reductions in energy. Showering at night is more likely to make use of solar energy than showering in the morning. Restricting the timer settings within the Offpeak period may also help, depending on when hot water is used.

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ESCOs, iGrid, and the Regulator.

The “intelligent Grid” is more likely an evolutionary process rather than a centrally designed, administered, and controlled collection of technologies that “runs energy”. I think it will be driven by ESCOS, starting in the industrial and commercial area (it has already begun), migrating down through building managers to aggregated domestic, and up through large users to generators, mixing in renewables as it goes. It is underway. It will not be influenced either way by the presence or absence of smart meters.

However Regulation is another thing. It can be stopped by our current regulatory environment. Australia has a lot of unnecessary and simply restrictive regulation that is clogging up the market, effectively preventing a meaningful demand side, and generally getting in the way of efficiencies. The Australian market is derived from the UK, but has simply failed to keep up with reforms in the UK that have seen these restrictions swept away.

Reform requires policy change; in Australia that means COAG. The Regulator is charged with executing policy, which is does very well. It is also responsible for providing the most credible advice to – let’s face it – a less than technically brilliant group of bureaucrats and politicians. Constructive proposals made by competant bodies have simply been ignored, along with reforms in other places. It is time for the Regulator to play its proper role in industry reform.

The future for ESCOs is bright: ESCOs currently servicing the commercial and industrial sector can address the domestic sector through networking and the aggregation of fewer than 100 dwellings. If electric vehicals become widely used the opportunities are enormous.

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Why Utilities like Zigbee

The amount of money made by privately owned Australian electricity distributors is directly proportional to their capital. They like Zigbee because Zigbee is a capital expense; other forms of communication involve either involve recurring costs or – horror – letting in consumers and ESCOs on the deal. Zigbee places administration and control of the “home area network”, as well as control of the devices attached to it, in their hands. Improved efficiency in any form (physical, financial) threatens their bottom line.

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WattWatchers product status

Yesterday we received off-tool parts for WattWatchers Auditor and Appliance Manager products. The Auditor case clips together perfectly (no fasteners). Our industrial designer group and the toolmakers have done a great job. The Auditor will definitely be the best looking guy on the DIN rail. Compliance work is proceeding, and there is more work to do on production procedures and documentation.

Some adjustments are being made to the UNO enclosure to improve the speaker performance, ease of manufacture, and some details relating to the LCD zebra strips. We have WiFi code running in the boards and so the product is demonstrable.

Object Consulting has ported the OurGreenHome iPhone app to iPAD – it looks stunning. Appearance is everything these days. Nobody much seems interested in the underlying data bases and memory-based realtime net-computing required to deliver the data with such low latency (7 seconds, including the 5 second measurement period).

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This might be a bit off-topic, but I can’t resist comment on the nuclear debate.

A common assertion is that the only available, and economic, alternative to coal is nuclear (with maybe gas filling in for a period of time it takes to build the plants).

There ARE other options. There are also great difficulties with nuclear in the context of the Australian National Energy Market.

To function at all, nuclear needs huge amounts of water for cooling. For the NEM, this mandates a nice seaside location. Difficult. Next: Our current grid is not designed to support injection from single sources that large. So take the cost of nuclear and double it to provide switchgear and additional transmission lines. Expensive. Next: Redundancy demands at least two plants, and a market that relies on only one to function. Double again.

So what are the options? First option: fix hot water. Instead if the state making asset-poor people subsidise asset-rich people with houses to install inefficient solar PV arrays, insist first that ALL the hot water used by that house be solar / renewable. This admittedly rules out pretty much all solar hot water systems, but it creates a 30% drop in domestic energy consumption. And it creates an immediate, superb, place to STORE RENEWABLE ENERGY. So much for the sun not shining and the wind not blowing.

Second option: behavioural change (see WattWatchers). All studies show 20% domestic reduction is available. Then there are peak-spreading, demand side strategies that more effectively use existing generation capacity (WattWatchers again). This requires policy change and heavy handed intervention in the strategies of utilities.

Third: stop population growth. It is now well established that this generation can’t plan, so we don’t deserve and can’t cope with more people. Anyway, we can’t expand for ever, why not stop now? See all conservation arguments. Or visit Bondi.

These measures will reduce carbon now, when the cumulative effects of carbon savings can accumulate. Once done, nuclear is even less necessary.

Oh. And if we ARE going to spend more on distribution, note that South Australia currently generates >20% of total energy with wind. It could be even more if it wasn’t limited by the poor distribution infrastructure close by Adelaide where the wind blows.

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Which Developer: Internal or External?

Your electronic system may include 3rd party subsystems such as GPS, WiFi, Zigbee, and Telco-connected radios. These subsystems may not be stable products, creating ongoing support and compliance issues. Instability is caused by firmware upgrades, hardware changes, parts and subsystems going obsolete, Telcos who make small but disruptive changes to protocols, power requirement changes, and so on. Discontinuity of supply may involve rework of your product hardware and firmware. When product instability occurs it sometimes requires time, and deep technical analysis to determine the cause of the symptoms, and then a development period to resolve the issue.

Subsystem instability is a very good reason for working with a developer in the first place, rather than hiring individuals for a limited period of time. If you choose a developer who is currently developing with the kinds of subsystems that will be in your system, the changes are he will identify and resolve your support issues before you realise they exist. At the very least he will have the familiarity, diagnostics, tools and environment to be able to re-create and resolve the problems.

Developers are exposed to many components and products. They are like chefs: always looking out for the latest ingredients and methods. This is a vital and necessary part of their business, and essential in the early stages of product concept and implementation. Only developers, or large companies with permanent development teams, can simply know enough to make good technology decisions.

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IP based power monitoring

WattWatcher Auditor pre-production is taking place this month. Off-tool samples of the custom plastic enclosures are due week3. Trials this year with 40 prototypes have driven several changes that simplify installation and provide for robust operation. Realtime data is web delivered through the OurGreenHome website. A rather spectacular, free, iPhone and iPad application will soon to be available through iTunes. Driven by real data from an Auditor it provides the ability to monitor whole-of-house energy with Class 1 meter accuracy and 7 second latency; with an Appliance Manager installed it provides direct measurement and control of appliances such as pool pumps.

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External WiFi antenna

The 2.4GHz antenna developed for the WattWatcher WiFi power meters installs directly onto 20mm electrical conduit, so is simple to install in an optimal location – outside a metal meter box, for instance. The power meters include an internal antenna, and a low loss galvanic isolation structure that ensures safety for the external antenna. The external antenna has slightly better transmit performance, and significantly better receive sensitivity due to the additional distance from noisy electronics. It is manufactured with 700mm of RG174 and is RP-SMA terminated. The antenna gain is 5dB, cable loss is less than 2dB for a nett gain better than 3dB. Any required antenna placement and orientation can be easily achieved using off the shelf conduit fittings (elbows, T-pieces, clamps etc.).

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Low power WiFi

WiFi devices can use very little power and have better system performance that other low power battery operated radio systems. The WiFi Access Point knows about sleeping devices, and stores any packets aimed in their direction. The Access Point includes information about stored packets in the beacons that it transmits 10 times each second. The sleeping device can discover pending data by waking up for short periods (say just before every 50th beacon).  This requires very little energy. Through this mechanism, a low power WiFi device can have battery life comparable to other low power radios, and at the same time be responsive to system demands, and even operate as a server.

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