NERSA and Eskom keep missing people with their rules

 https://mybroadband.co.za/news/energy/438552-charging-solar-power-users-higher-prices-in-south-africa-eskoms-plans.html?utm_source=newsletter

"The regulator recently adopted a principles document which included categorising South African power users into three main groups:

"Big power users — characterised by consistent day and night usage.

"Normal power users — characterised by high demand in the mornings and evenings, with lower power usage during the day.

"On-grid solar and self-generating power users — characterised by fluctuating power demands dependent on the availability of sunlight.

Nersa also adopted a principle that each user category must pay tariffs based on the actual cost of providing them with electricity."

As usual those of us with battery backup systems are left out. Since 2008, I've been offering to sell electricity to the grid at peak times, which could be outside solar hours, usually 6 till 8am and 4 to 7pm. How to do this? Use batteries, and East West Solar Panels lengthening the solar day and flattening the curve (someone stole this term from solar users). It is actually stupid to have all your panels facing north in a battery backup system, as you want to lengthen the solar day as much as possible.

As an alternative to this, I can remove myself from the grid at peak times and never use electricity at peak times. I should get a much better rate for this.

For decades Eskom and Nersa have been going on about "solar users generating lots of electricity during the day and then consuming it at night." That is old. It's grid tie, without batteries.

Most people in South Africa don't want load shedding and therefore have batteries in their solar systems. Some have batteries and inverters only and no solar. All these people can contribute to the grid reducing the need for Eskom to spend Billions of Rands per month on expensive diesel generation running at peak times.

#electricity #peakdemand #solarelectricity #tariff

Tariff increases will kill incentives to save electricity and water

David Lipschitz Letter to the Cape Times published Mon 8 May 2017 in their Insight Section

THE City of Cape Town has published their draft tariffs for the 2017/18 financial year. Search for "draft electricity consumptive tariffs 2017/18" on the City's web site.

My calculations are based on people living in accommodation valued at more than R1 million. The poor still get their incentives and in fact the poor using more than 350 kWh per month will get up to 23.5% discount of their electricity usage.

And service fees for large users are increasing too, in one case by as much as 120%, so we can all look forward to higher inflation come July when this city, that works for us, makes it more difficult to work with us.

My calculations show that for someone using 600 kWh a month the price increase is 2.8% and someone using 1200 kWh a month the price increase is also 2.8%.

For 600 kWh it changes from R1125 domestic tariff excluding service fee, to R1156 home tariff including the fee, a 2.8% increase.

The 1200 kWh changes from R2493 domestic tariff excluding service fee to R2562 home tariff including the service fee, 2.8% increase.

But 300 kWh changes from R562 to R702, a 25% increase.

And 100 kWh changes from R187 to R400, a 214% increase.

For myself, a few years ago, we were changed from "Lifeline" to "Domestic" and from July this year we will be changed to "Home".

Being incentivised to use less has fallen by the wayside.

Note that the free water allowance is falling away! So if you are using 10 kL a month, and you were paying R66, you will now be paying R98, a 48% increase. Plus the free sewerage component is also falling away, increasing this increase even further.

It seems to me that the financial incentives to save electricity and water will cease on July 1, when these new measures come into play.

At some point, economics says that if you are prepared to pay the price, you can get what you need.

People might choose to buy more water and electricity instead of other luxuries.

And our water crisis will get much worse as people's financial psychological incentive to save is removed.

We might even end up with load shedding again, as people stop worrying about how much electricity they are using and just use as much as they want.

I tend to think that energy efficiency measures will simply go out of the window and people will use as much as they want.

This seems to be the case in my mind, where even though I am a very energy-conscious customer, I just don't see the point of saving electricity and water, when perhaps I can afford to pay the higher rates. There is just no incentive anymore for saving.

The city is putting up their prices. They are telling their customers "if you can afford it, we will supply you; and if you can't afford it, please move to another city".

The free water allowance is falling away, which means that the incentive to do all you can to use less than 6 kL of water a month, and boast about not pay anything, is meaningless.

Grid tie, without batteries, solar electric is already cheaper than City of Cape Town electricity. It could be up to half the price, depending on circumstances. And battery capability is increasing in leaps and bounds and prices are coming down, so we will soon be at grid parity with batteries. Grid parity is where one can make one's own electricity cheaper than one can buy it.

As I've been writing in this newspaper for years, it is time for residents to work together to produce their own electricity and water, at a much cheaper cost than our government can provide it, and in fact sell this cheap electricity and water to the city and to our residential neighbours.

Besides paying or moving, another opportunity is to move into "townships". This way I get a much cheaper house, with all the benefits that come with this, and I can afford to pay for security with the savings I get.

I think we will see enclaves of "rich people" living in the middle of townships, within the next few years. The "poor" won't want to move into "rich" areas, when they see the overtaxed rich, moving to them.

Lastly, existing homeowners who have paid for infrastructure numerous times are in effect subsidising new entrants into the market. New suburbs and new parts of suburbs and densification is happening all over the place. It seems to me that these people are being way undercharged for the services they need.

Lets suppose that a new power station is required for a new suburb.

Why should the entire population be forced to pay for it? And why do new suburbs need external power stations in any case?

• Lipschitz is an energy analyst and owner of My Power Station.

Life or Death Matter. David Lipschitz letter to the Cape Times published Tue 8 Mar 2016

According to the City of Cape Town web site, dam levels are at 38.7 percent and last week they were at 40.5 percent. In 2014 they were at 81.2 percent. Theoretically Cape Town has 21 months of water left, assuming no rain, but with dams silting up, who knows how much water we really have?

See http://www.capetown.gov.za/en/water/pages/weeklydamlevels.aspx

Cape Town's dramatic population increase over the past 20 years, together with hardly any increase in dams, combined with the drought over the past two years, and lack of imagination in the City of Cape Town council and at provincial level, had led to the problem.

Some people are calling for "Level 3" water savings. If the City implements Level 3 water savings, there will be an even more dramatic reduction in income for the City.

Many people have already installed pool covers and with a reduction in watering allowances on gardens, people are seeing a 50 percent-plus drop in water consumption, with an associated decrease in income going to the City, even with the massive price increases for large, home based water users.

At Level 3, people might find ways to stop buying City water altogether! People and organisations are already finding ways not to buy electricity due to the massive price increases, together with less Eskom and municipality electricity being available. Cape Town's lack of water is a big problem, made much worse by decades of bad planning, and bad thinking! Desalination could solve our problem, but government isn't thinking about that - yet.

If people were allowed to install rooftop solar electric systems on their houses, and if we were allowed to feed our excess electricity into the grid at a reasonable price, the excess electricity could be used to desalinate water. This is much cheaper than building new dams, and dams take years to build and need rain and mountain water - and we just don't have this time, nor, with climate change, can we expect the needed rain to materialise anytime soon.

If the City runs out of water, we'll all be dead within four days, so perhaps allowing rooftop electricity is truly the answer to many of our problems! Many people have planned their retirement, but isn't it better to plan to be alive next week?

Life or Death Matter: David Lipschitz's letter in the Cape Times on 8th March 2016

Life or Death Matter

According to the City of Cape Town web site, dam levels are at 38.7 percent, while last week they were at 40.5 percent. In 2014 they were at 81.2 percent. Theoretically Cape Town has 21 months of water left, assuming no rain, but with dams silting up, who knows how much water we really have?

See http://www.capetown.gov.za/en/water/pages/weeklydamlevels.aspx

Cape Town's dramatic population increase over the past 20 years, together with hardly any increase in dams, combined with the drought over the past two years, and lack of imagination in the City of Cape Town council and at provincial level, led to the problem.

Some people are calling for "Level 3" water savings. If the City implements Level 3 water savings, there will be an even more dramatic reduction in income for the City.

Many people have already installed pool covers and with a reduction in watering allowances on gardens, people are seeing a 50 percent-plus drop in water consumption, with an associated decrease in income going to the City, even with the massive price increases for large, home-based water users.

At Level 3, people might find ways to stop buying City water altogether! People and organisations are already finding ways not to buy electricity due to the massive price increases, together with less Eskom and municipality electricity being available. Cape Town's lack of water is a big problem, made much worse by decades of bad planning, and bad thinking! Desalination could solve our problem, but government isn't thinking about that - yet.

If people were allowed to install roof top solar electric systems on their houses, and if we were allowed to feed our excess electricity into the grid at a reasonable price, the excess electricity generated could be used to desalinate water. This is much cheaper than building new dams, and dams take years to build and need rain and mountain water - and we just don't have this time, nor, with climate change, can we expect the needed rain anytime soon.

If the City runs out of water, we'll all be dead within four days, so perhaps allowing rooftop electricity is truly the answer! Many people have planned their retirement, but isn't it better to plan to be alive next week?

Staffing the roof-top Solar Revolution in (South) Africa

"Staffing the roof-top solar revolution in (South) Africa"

South Africa and Africa’s educational level and system lends itself to a Renewable Energy powered electrical system. We don’t have the time or resources to build coal or nuclear plants anymore. So what are we waiting for, and why are we wasting time on out of date technology that we cannot support and where local people will not be employed?

http://www.sabreakingnews.co.za/2015/09/15/staffing-the-roof-top-solar-revolution/

Activating the solar revolution in South Africa

Article that appeared in SA Breaking news this morning: titled: 

"Dear Investor: Put your money in Solar Leasing to build new power in SA"

Energy Analyst David Lipschitz writes a letter to an international financial institution on ideas for projects in South Africa:

Dear Investor

Thank you very much for your email and for your generous offer of mutual cooperation.

I am particularly interested in getting Solar / Energy Leasing For Small Scale Projects going in South Africa. Up to now, investors haven’t been particularly interested in Solar Leasing because of government rules, but thousands and perhaps tens of thousands of private people, companies and organisations are installing battery based renewable energy systems, or renewable energy systems which do not feed the national grid, and this is legal, up to 1 MW. Hundreds more want to install, but don’t want to have the finance in their bank accounts or in their homeowner bonds or on their balance sheets. It looks like a lot of money to pay R100 000 ($ 7200) for a homeowner or R10 million ($ 720 000) for a business owner, even if the project is cash flow positive from month one and/ or even if the investment means that load shedding (administered power failures) won’t affect the home or business owner.

One should note that the ANC government in their Integrated Resource Plan (IRP) 2010 Update 2013 said that electricity users might install renewable energy and embedded generation with or without the consent of government and with or without government incentives. This is happening, mainly because of the three government “incentives” of overinflated electricity prices, load shedding, and lack of promised electricity supply, forcing electricity users to find alternatives.

Of course our target market would be anyone with a roof and with an existing electrical supply. The wires are already in place. And no Environmental Impact Assessments (EIAs) or big monetary tendering outlay are required.

It is also good for South Africa, as in my opinion, we should have 426 GW of electricity, and we have 33 GW. Eskom’s own projections show that we should have 50 GW by now, and other commentators are saying we should have between 50 and 100 GW by now.

Whatever the total is, it should be substantially more than it is now, and within the next 20 years, almost all of Eskom’s existing power stations will reach end of life, which implies a massive build out and requirement for energy in South Africa and Southern Africa. At least 100 GW of new build will be required in the next 20 years. Private people and capital can provide this build out at a third of Eskom’s capital cost; and it will be completed on time and to budget and to the desired quality.

We are also suffering from droughts, and it makes sense to use spare capacity in a renewable energy system (and even in a fossil fuel system) firstly for pumped storage, secondly for charging batteries, thirdly for making hydrogen, which can be converted to methane and easily stored and used in gas-engines (generators which use gas as the fuel source), and then for desalination. These energy storage options and desalination are essentially free in a Renewable Energy system, besides the capital and OMI (operations, maintenance and insurance) cost.

Furthermore there are private generators of energy (called Independent Power Producers – IPPs) in South Africa, who have built power stations, and who are being paid for electricity, but who aren’t physically delivering that electricity, because Eskom hasn’t built the Transmission and Distribution (T&D) network yet. The other problem with IPPs is that they are simply “off-balance sheet financing” for Eskom, where Eskom is still committed to payments for 20 years, just as if they had borrowed the money and built the power stations themselves.

Embedded Generation already has all the T&D networks in place. And it reduces the maintenance requirement on the grid. Our politicians don’t like it though as they believe that it will reduce their income, but imagine a grid with at least three times as much electricity as now, and where all that electricity flows via a nationally owned electricity grid. The carriers of the electricity (government) would make substantially more money than they make now, but they don’t listen to me, and perhaps they will listen to you or us?

I realise that you probably don’t want to invest in hundreds or perhaps thousands of small projects, but what of funding a New Specialist Local Finance House or New Bank, which specialises in Solar Leasing?

I believe that you could achieve substantially more than your desired 10% ROI (Return on Investment) for the project, or you could use the surplus to fund projects in underprivileged areas.

I look forward to your reply and to continuing our discussions.

– David Lipschitz FSAAEA, computer scientist, mentor and energy analyst with a Bachelor of Science Honours and an MBA, has run a Software Development business since 1994 and an Energy business since 2008. David motivates people to change the way they think about their environment and shows people that it is possible to live a sustainable lifestyle with minimal impact on the earth. Keynote, conference and workshop topics include energy efficiency, load shedding, and producing electricity.

See http://www.sabreakingnews.co.za/2015/09/07/dear-investor-put-your-money-in-small-scale-projects/

Nuclear Power for South Africa?

The picture above is from the Green Print Nuclear is Cool Poster published in Schools by the South African government in 2009.

Nuclear Power for South Africa: 9.6 GW, ie 9,600,000,000 Watts.

R1 Trillion: R1,000,000,000,000 capital expenditure.

R104 per watt! Photovoltaic Systems with batteries are about R35 per watt.

To repay R1 trillion? R10 Billion: R10,000,000,000 per month repayments over 20 years at 10%.

4 million tax payers in South Africa, but 5% of the taxpayers pay 50% of the tax.

So if you happen to be one of these 5%, you are one of 200,000 people who need to pay R5,000,000,000 per month.

Which is R25,000 per month!

Something to look forward to in 10 years time? Without even getting electricity, and like Medupi and Kusile with no guarantee that the electricity will be available!

There and the other 3,800,000 people pay R1,315 per month.

And that's what the rich (another word for taxpayers) are being asked to do in South Africa, for "clean, reliable, environmentally" nuclear electricity.

Coal would be about R300,000.000,000 for the 9.6 GW, which is about R35 per Watt. But you still need 5,200 tons of coal per hour to run 9.6 GW of coal power stations!

And as you know coal and nuclear power stations don't run 24 hours a day 365 days a year. They need maintenance, shutdowns, refuelling, etc. And sometimes they just break.

What to do about it?

Call me, or book me, and I'll show you another way of thinking.

Vital Solution Ignored. Letter in Cape Times on 11th March 2015

NERSA has published a request for comment on their web site regarding "net metering" and embedded generation (EG).

In South Africa, peak demand typically happens between 7am and 10am in the morning, and 6pm and 8pm in the evening.

The document assumes that EG cannot help with peak demand and ignores battery-based systems, fuel cells, biodigestors running on farms at peak times, sewerage-mining and so on.

This fundamental assumption causes the document to, again, ignore the huge potential of homeowners and rooftop owners to completely remove their peak demand and thus effectively supply the grid with electricity at peak time. Meaning South Africa's peaking power stations will not be needed, and the economy will expand.

Note that here is my full email to NERSA, based on this document:

Dear NERSA

I have read the latest discussion document dated 25th February 2015 as well as the draft discussion document dated 10th December 2014 and I have the following comments and observations:

1) The new document excludes the PV installation list from around the country. This is unfortunate as your readers will not have an idea of the scale of existing systems already being installed. Of-course this list ignores systems less than 1 MW, but nevertheless it is an interesting list.

2) The list of concerns has also been left out. One of the many reasons for the poor adoption of Embedded Generation in South Africa is because government misunderstands how important electricity generation is for the economy, and instead focuses on potential lost generation and compensation.

3) It is unfortunate that the System Profile Impact graphs have been ignored in the latest version. These graphs show how Renewable Energy will impact on the load profile of the grid. Having this information means that installers and users of EG can make proposals to move their loads to when the sun is shining.

4) Both documents assume that EG cannot help with peak demand and ignore battery based systems, fuel cells, biodigestors running on farms at peak times, sewerage-mining, etc. This fundamental assumption causes the document to again ignore the huge potential of homeowners and roof top owners to completely remove their peak demand and thus effectively supply the grid with up to 17 GW of electricity at peak time, meaning that South Africa's peaking power stations will not be needed, the economy will expand, etc.

Please acknowledge receipt of this email and add me to your communication database for the Public Hearings, etc.

Yours faithfully,
David Lipschitz

What if it rains and I've got a solar electric photovoltaic (PV) system?

What if it rains and I've got a photovoltaic (PV) (solar electric) system?

A question I get all the time!!!

Well it's raining now (13th February at 11.15am) and my 1 KW PV system is generating 190 Watts.

We are currently using less than 190 Watts in the house, therefore we have excess energy being used to recharge the batteries. If we have a power failure now or Load Shedding, we won't use our batteries.

One should also note that Germany is the world's biggest PV installer and they've been installing in a big way since 1991. They only have 40% of the solar irradiation of South Africa and therefore for the same capital cost, South African PV users get 2.5 times the output as compared with German PV users.

Battery related questions in a backup system which can be used during Load Shedding in South Africa

Here is an answer I just posted on Facebook: "Have I been given the wrong info? I hear that the battery replacement cycle is rather short and therefore costly."

Hi Pat.

If you buy the 100 or 105AH "Solar Storage" batteries that look like car batteries, but which are called "Solar Storage", they will last about 2 years and then even though they say that are "sealed" I had 8 of these batteries and managed to refill them after two years to that they lasted 4 years. But their performance wasn't great.

18 months ago I upgraded to "Deep Cycle" batteries, 260 AH 12 Volt SonX batteries. The 4 SonX cost about R20,000 instead of the first set which cost about R12,000. But they are firstly 520 AH at 24 Volts instead of 420 AH at 24 Volts and secondly their performance is excellent. They last a lot longer than the original batteries.

And then the specification says they should last 7 years, but I'm hoping they will last longer than this, but even 7 years will be excellent. Note that in a battery system design, one should design the system to not use more than 30% of the battery capacity on a regular (daily) basis and only use 50% on a very irregular basis. This way the batteries are looked after and will last the specified time.

Having said all this, the inverters should last 12 years and the most of the photovoltaic (PV) panels are guaranteed for 30 years, with the PV panels performance deteriorating to 90% of their rated capacity after 12 years and to 80% of their rated capacity after 30 years.

So relative to inverters and PV panels, batteries don't last as long and therefore need to be replaced more often and therefore are relatively more expensive. But the benefits they give you far exceed their costs, in my opinion.

One should also note that if you have a "battery system", you need more components than on a "grid tie system" without batteries and therefore a system with a battery costs more than just adding the additional battery bank. And there is more maintenance on a battery system although the systems can be programmed to look after themselves and send warning system messages or emails or sms's if there is a problem.

Set 1: Price R12,500: Lasted 2 years. The second 2 years battery performance was really poor. Equals R6,250 per annum.

Set 2: R20,000: Should last 7 years: R2857 per annum.

These calculations exclude interest and the Cost of Capital, but I think the point is made.

Rain and Solar-Electric PV Photovoltaic Systems

What if it rains and I've got a photovoltaic (PV) (solar electric) system?

A question I get all the time!!!

Well it's raining now and my 1 KW PV system is generating 190 Watts. It's a thin film system so it will be interesting to see how crystalline systems are performing.

We are currently using less than 190 Watts in the house, therefore we have excess energy being used to recharge the batteries. If we have a power failure now or Load Shedding, we won't use our batteries.

Dramatic Slow Down in Solar Electric (Renewable Energy) Training in South Africa

How to dramatically slow down renewable energy in South Africa. Take a qualification which takes a month in the USA and make it 2.5 years in South Africa!!

These are my official comments:

"2.5 years to do something that can be done in one month in the USA.

"I agree that we need inspectors and perhaps this qualification is more suited to inspectors. However, there are many people who are already installing very competent systems in South Africa and some like mine, which meet the USA NEC Article 690 requirements as far as possible."

http://www.record.org.za/news/item/the-summary-of-qualification-content-pv-technician-for-public-comment#comment-30461

Gecko Rock Solar Electric PV Installation in September 2010

Gecko Rock 8 minute installation and learning video

(as at 19th February 2014, over 2,000 people have watched this video)

(I removed the video in June 2016, and put it back in December 2016)

Gecko Rock (Jonathan Deal) Interview 1 year later

(I removed the video in June 2016, and put it back in December 2016)

Videos filmed and edited by Antony Stone at Big Bang Stunts and Effects

The Team:

Designers: David Lipschitz and Peter Burden
Main Installer: Peter Burden
Metalwork: Designed and installed by Steven Mulder
Videos: Antony Stone

The Client:

Jonathan Deal at Gecko Rock

Specifications:

Overview

• 1.6 kilowatt photovoltaic array with 24 Volt 675 Amp Hour battery bank and 1,200 watt inverter charger with generator backup
• 8 kwh of battery backup
• 8 kwh of average daily solar production from the photovoltaic array

• Location: Gecko Rock, 25 km South South East of Touwsriver, Western Cape, South Africa
• Solar Resource: approximately 5 average peak sun-hours
• Photovoltaic Array Size: 1.62 kW (1,620 watts)
• Nominal Voltage Batteries: 24 Volts
• Nominal Voltage Array: 72 Volts
• Array Voltage at Max Power: 108.6 Volts
• Array DC Current at Max Power: 15 Amps
• Battery Amp Hours: 675 Ah (amp hours) at 20-hour discharge rate. Multiplied by 24 Volts and allowing for a 50% maximum depth of discharge = 8.1 kWh in the batteries for overnight and overcast periods
• Record Low Temperature: unknown; we have allowed for Minus 15 degrees Celsius (during day light (operating) hours)
• Average Low Temperature: 2.2 degrees Celsius in July
• Average High Temperature: 28.6 degrees Celsius in February
• Average Daily Production: 8.1 kWh
• Average Electricity Available after taking account of efficiencies (or inefficiencies): Allow 7% for inverter loss; 20% loss for battery charge/discharge from photovoltaic array; and 2% voltage drop on the cabling: 8.1 kwh * 0.93 & 0.8 * 0.98 = 5.9 kwh per day of usable electricity (daily average over the entire year)

PV System Components:

• 9 Tenesol TE1700 at 24 Volt nominal: 180 Wp STC, 36.2 Vmp, 5 Imp, 44.4 Voc, 5.4 Isc (133.2 Volts open circuit for the array (at zero amps, i.e. first thing in the morning) and 16.2 Amps Short Circuit current for the array)
• Array: 1 “string” of 3 “panels” with 3 “modules” in each panel. Total 9 Modules, 1,620 Watts total
• Array installation: Dual-axis (manual) trackers designed by SolarSells, and enhanced, built and installed by Intricate Steel
• Inverters: 1 x 24 Volt Victron 1200 Watt multi-plus Inverter/Charger allowing 24 Volt DC to 220 Volt AC conversion of electricity and allowing automatic synchronisation of a generator input into the system to supplement the batteries in the case of long cloudy periods
• Solar Charge Controllers: 1 x 80 Amp Outback FM80 MPPT (maximum power point tracking) controller. The FM80 allows array sizes up to 2,000 Watts when charging at 24 Volts. The FM80 allows one to use a higher output voltage PV array with a lower voltage battery, such as charging a 24 VDC battery with a 72 VDC array. This reduces wire size (and cost) and power loss from the PV array to the battery/inverter location and maximises the performance of the PV system
• Batteries: Deep Cycle: 12 x 6 Volt Trojan T105′s in 24 Volt nominal configuration, i.e. 3 banks (in parallel) of 4 batteries (in series) making 24 Volts nominal and 675 Amp Hours capacity. Each 6 volt battery weighs 28 kg making a total battery bank weight of 336 kg. We expect the batteries to last about 8 years with an average discharge of 20% and a maximum discharge of 50%. The batteries have a 2 year free replacement guarantee assuming they are looked after and “watered”, i.e. the battery de-ionised water is checked and filled as required. We can tell how the batteries have been used by looking at the information on the Victron Battery Status Monitor. The Trojan batteries are designed in the USA and assembled in Cape Town
• Generator: 5 kw Honda
• System performance metering: Victron Battery Status Monitor BM 600 for DC performance and battery monitoring; Efergy e2 Electricity Monitor for AC performance and historical AC kwh tracking
• 2 Earth spikes and open earthing cabling allowing all metal work to be earthed. System and Equipment negative grounding. We have used USA NEC Article 690 rules as far as possible as there aren’t standards for PV systems in South Africa yet.

Update:

Subsequent to this original installation, Jonathan upgraded to 3 x 1.6 KW Victron Inverters giving 4.8 KW. He also upgraded his battery bank to 1125 AH at 24 Volts. Interestingly he discovered that he doesn't need to cook with gas anymore and that he can power his cooking with his microwave / convection oven. This provided an unexpected saving with the system.