Friday, September 24, 2010

Faulty / inefficient aircon unit costing $228 per year in standby!

After Scott's first email, that we posted here:

... we got another email from him this morning:

"My journey of discovery didn't end at the hot water system.

My night time standby power has been consistently over 200 watts since I installed the ENVI. From my googling the average for Australia is 86 watts.... So I turned absolutely everything off in the house. Still reading 140 watts?

Next stop was the power board. I started by turning the obvious circuits off. Stovetop, oven, aircon ciruit.

As soon as I turned the airco circuit off, the meter dropped [130W] to 10 watts. I was dumb founded. The aircon was not running, but turning the circuit back on showed it consumes 130 watts in standby.

I confirmed it was the outdoor component of the split system by turning the isolation switch off at the outdoor unit.

[Once I'd turned this off, the house draws] only 10 watts in use (which is the dc converters for the down lights)."

We did some quick maths on Scott's findings.

130W = 0.13kW.

0.13 x 24 hours x 365 days = 1138 kWh (or units of electricity) used per year!

At $0.20 per kWh (that's an average across Australia) that's $228 a year.

Over ten years, that's $2280, assuming that power prices aren't going up!

Using the Current Cost ENVI to hunt down faulty appliances

We received the following email from Scott today - this is unedited:

"I also want to give the Envi power meter a huge thumbs up. My house has been chewing through the power (average 30kwh/day) and I’ve been scratching my head trying to work out why. We don’t have a pool, we have a heat pump hot water system, we have low wattage bulbs, insulation in the roof, we hardly ever use the dryer or split airco.

By installing the ENVI power meter I was able to find out that the heat pump hot water system was running for a while then overheating. As a failsafe “feature” the heat pump then uses an electric boost to heat the water to temp. Imagine my surprise when the meter went from 1kw (compressor) to 3kw (boost). There is no obvious sign that there is a fault and has probably been happening since install going off my power bills. I can’t wait to see how much I’ll save on the next power bill now that the heat pump is fixed. With the ENVI I’ll be able to keep a close eye on it in the future. It’s well and truly paid for itself in the first month (and then some)."

Monday, September 13, 2010

Solving Driver Issues with the Current Cost ENVI Prolific PL2303 USB Cable

A couple of our customers have recently had some strange issues with both Vista and Windows 7 x64 with installing the drivers for the USB Cable (which contains a Prolific PL2303 chip).

Anyway, the following link seems to have solved everyone's problems:

Which lead to:

Which lead to this: which is version 1013 (WHQL Win 7 x64 Version

Now, we can't guarantee that this software isn't going to eat your computer alive from the inside because it isn't our software and we haven't tested it. However, it seems to have solved the issues.

Sunday, September 12, 2010

Use the Current Cost ENVI to determine if your transformerless solar inverter is using power after dark

We’ve recently had a few reports of “faulty” ENVIs, whereby people are reporting power readings from their solar panels on the ENVI after dark.

One of our customers thought initially that it could be power being generated by moonlight!

In actual fact, it appears that the inverter is drawing power after dark, typically 70-90W, but occasionally spiking to over 200W.

The reaction from the solar inverter manufacturers has been that the ENVI must be faulty, or it could be that the inverter is causing interference to the transmission. Naturally, we have been very worried about this, and have been working our socks of to work out what is going on. This included using a variety of different wireless electricity meters on the same circuit – they all agreed to within a couple of Watts, ruling out the interference suggestion.

Eventually, the answers have become clear. A Fluke Multimeter was reading 0.31 Amps being drawn after dark. A service engineer also reported a power draw of 300mA. 0.31A x 240V = 74.4 Watts.

This has been established in two cases so far, and in no cases have we received any evidence to show that the Current Cost ENVI is reading incorrectly. We’re not going to name the manufacturers involved here for liability reasons, and will continue to keep you posted with any new information we receive.

Thursday, September 2, 2010

Using the Current Cost ENVI to hunt down faulty appliances

We just received an email from a lady who we spoke with a month or so ago.

She had just received a Current Cost ENVI from us (, and was concerned about the readings it was showing. With nothing on in the house she couldn't get the power consumption down to below 6-700 Watts, even by turning the fridges and freezer off.

It turns out that two things were happening:
1) The Septic System Sludge Pump was stuck on and running 24 hours a day
2) The fan on the top (that is on 24 hours a day) was pulling 250 - 300W - considerably more than the advertised 100W.

By finding and solving these two issues, we think she'll have saved $700 a year (workings below) just with the fan, which she is replacing completely for a whirlybird.

300 W = 0.3 kW
0.3 kW x 24 hours = 8 kWh = 8 units of electricity
Average electricity cost = $0.22 / kWh
Total cost per year = 8 kWh x $0.22 x 365 = $700 per year.

Get a Current Cost ENVI today and discover where your power is going.