XYLENE POWER LTD.

INTERRUPTIBLE ELECTRICITY HISTORY

DEFINITIONS:

Clean Electricity is electricity that is generated without emission of fossil CO2.

Dependable Electric Power is the electric power drawn by loads which need electricity that is almost always available.

Interruptible Electric Power is the total available clean electric power less the Dependable Electric Power.

Annual Interruptible Electric Energy Supply is the time integral of the Interruptible Electric Power over one year.
 

ORIGIN OF INTERRUPTIBLE ELECTRICITY:
Interruptible Electricity is a byproduct of production of dependable clean electricity. The clean electricity supply capacity varies due to variations in precipitation, sunlight, wind and equipment maintenance. The dependable electricity load varies due to changes in the power requirements of dependable electricity customers.

In order for the clean electricity supply to be dependable the clean electricity supply capacity must always exceed the dependable electricity load by at least 15% on the peak load instant of each year. However, due to seasonal and daily changes in both the clean electricity supply capacity and the dependable electricity load, the difference, which is the interruptible electricity supply capacity, varies over a wide range.

The graph below shows the difference between the clean electricity supply capacity and the dependable electricity load at night during 2016. Some of this interruptible electricity comes from intermittent wind and solar resources and some from dependable hydro and nuclear resources.

Source: OSPE Energy Task Force, April 2017.
 

In practical implementation, although the instantaneous interruptible electricity supply capacity at any instant in time is not predictable, the average interruptible electricity supply over a year is both substantial and quite predictable.
 

ECONOMIC LOSSES:
As a result of past poor Ontario government energy policy, which has continued for over a decade, each year the province of Ontario has wasted about $2 billion in economic benefits by either discarding surplus interruptible electricity or by exporting this surplus interruptible electricity at bargain basement prices. This surplus interruptible electricity should instead be used to charge battery electric vehicles, to directly displace fossil fuels that are currently used for comfort heating and to produce seasonably storable synthetic fuels. Doing so would substantially reduce both costs to consumers and their CO2 emissions.
 

OSPE SLIDE SET:
Paul Acchione of the Ontario Society of Professional Engineers (OSPE) explains in a slide set how we could prevent the aforementioned waste of intermittently available non-fossil electricity.
 

ONTARIO'S ELECTRICITY SYSTEM DESIGN:
The Ontario electricity system is designed to have sufficient generation and transmission capacity to meet the Ontario’s yearly peak electricity demand with sufficient reserve capacity to ensure that the total customer demand for electricity will always be met in spite of unplanned equipment outages.

Prior to 2007 most of the reserve generation capacity was provided by coal-fired power plants. One consequence of replacing the coal-fired generation with clean nuclear, hydro, wind and solar generation is that much of the time this clean generation can be used to supply low-cost interruptible electricity. The marginal cost of interruptible electricity is almost nothing because providing it requires little or no extra fuel or equipment. Hence the incremental cost of producing and delivering this interruptible electricity to customers is almost zero.

Interruptible electricity loads should be enabled or disabled by the IESO (Independent Electricity System Operator) to keep the total electricity load nearly equal to the available clean generation. Interruptible electricity loads should be disabled when fossil fuel generation is operating.

The available interruptible electricity can be used to displace fuel oil and propane in stationary hybrid heating systems and can be used for producing hydrogen gas through electrolysis. There are other potential uses for the interruptible electricity such as charging of battery electric vehicles.

The Ontario Society of Professional Engineers (OSPE) has estimated that the amount of interruptible electrical energy available in Ontario in 2020 was about 20 TWh, i.e., about one-seventh of total Ontario’s total electricity production. Furthermore, after nuclear power plant refurbishment, this amount is projected to increase in future years as additional nuclear generation enters service.

The amount of idle equipment capacity presently available to produce clean interruptible electric power in Ontario varies over time, ranging from zero to about 6,000 megawatts, depending on the time-of-day and the season.
 

POTENTIAL ECONOMIC AND ENVIRONMENTAL BENEFITS TO ONTARIO:
Ontario’s present retail electricity price structure does not allow efficient use of the province’s available interruptible electricity. Instead of making this interruptible electricity available to Ontario electricity customers present Ontario legislation causes this electricity to be either discarded or to be exported at a very low price (~ $0.02 / kWh). Why not sell this interruptible energy to Ontario customers at the same low price?

By suitably changing the electricity rate structure it is easy to prevent electricity consumers from using inexpensive interruptible electricity to displace more expensive dependable electricity.

In rural Ontario, where natural gas service is unavailable, interruptible electrical energy could partially displace furnace oil and propane.

Hence, if rural Ontario residents used all of the available interruptible electricity to displace furnace oil, then their net economic benefit would exceed $2 billion per year.

(20 TWh / yr.) x (10^9 kWh / TWh) x ($.12472 - $0.02) / kWh = $2.094 billion / yr.

There is another benefit being foregone – the reduction in CO2 emissions that would result from the displacement of fossil fuel consumption by clean electricity. Thus Ontario’s current electricty price structure is resulting in both loss of economic benefits and loss of environmental benefits.
 

SOURCE OF THE PROBLEM:
The root source of this problem, which is enshrined in Ontario legislation, is that the cost of electricity is recovered from retail customers based on the number of kWhe the customer absorbs. Such a rate design is flawed for any power system but is particularly inefficient for one that does not produce energy with fossil fuels. The cost of electricity in Ontario is almost entirely determined by the recovery of capital investment and fixed operating costs of its generators, transmission and distribution systems. Due to minimal use of fossil fuels the cost of marginal energy in a non-fossil electricity system is usually less than 10% of the required revenue stream.

The owners of generation, transmission and distribution assets are mainly compensated through capacity payments ($/kWe) rather than energy payments ($/kWhe). Thus, it logically follows that each retail customer should be charged a monthly amount for grid access based that customer’s monthly peak electricity demand (measured in kWe, not kWhe), particularly during the hours of the power system’s peak demands. Interval meters provide the data needed to calculate the demand charges.

However, there would still be a need for charging a marginal energy price ($/kWhe) for fair allocation of the finite amount of available interruptible electricity. In order to provide local distribution companies with a modest price markup it may be necessary to index the retail energy price to the wholesale energy price.

The current retail price structure charges consumers a high price per kWh, which serves as a disincentive for consumers to substitute electric heating for fossil fuel heating even when available interruptible electricity is being discarded or exported at bargain basement prices. This policy is causing a massive loss in economic benefit and is causing unnecessary fossil fuel consumption with corresponding unnecessary provincial CO2 emissions.
 

WHO WINS? WHO LOSES?
Under the existing retail electricity rate structure the big winner is the fossil fuel industry, which sells more than $1 billion per year of otherwise unnecessary liquid fossil fuel for stationary heating in Ontario. The other winners are out-of-province parties that get to purchase Ontario’s surplus interruptible energy at bargain prices. One can expect these windfall financial beneficiaries to oppose any changes to the current electricity rate structure.

The big losers are Ontario’s electricity rate payers. Other losers are the province’s taxpayers who are financially responsible for paying a federal fossil carbon tax on the resulting excess CO2 emissions. And ultimately we all lose because of the foregone CO2 emission reduction.

Another loser is the rural Ontario work force. Primary industries that require electricity 24/7 for mineral extraction, base metal refining and paper production need a low blended electricity price per kWh to be internationally competitive. The recent past high blended price per kWh for 24/7 loads drove many of these primary industries out of Ontario.

Another significant loser is the Ontario public housing sector. The gradual change in electricity rate structure after 1981 disproportionately raised the cost of operating public housing so much that organizations such as the Toronto Community Housing Corporation (TCHC) do not have the financial resources required to maintain the public housing stock.
 

THE SOLUTION:
To fix this situation Ontario provincial legislation must be changed to allow a new retail rate structure for recovering the cost of electricity generation, transmission, distribution and regulation based on the principles described herein. It is essential that all of the non-fossil electricity that is available in Ontario be effectively used in Ontario, not discarded or exported. Making this energy available to Ontario consumers will reduce the average blended cost per kWhe of electricity without reducing the gross electricity revenue.

Until the marginal energy ($/kwh) charges are substantially reduced electricity consumers will have no incentive to displace fossil fuels supplied from outside Ontario with available surplus clean electricity generated within Ontario. Absent this important electricity rate structure change most of Ontario's wind and solar electricity generation and part of its hydro and nuclear generation will continue to be wasted.

For the sake of its own citizens, Ontario’s legislated retail electricity rate structure must change.
 

SEPTEMBER 2020 NEWS RELEASES:
National Post

Toronto Star

OSPE

INTERRUPTIBLE ELECTRICITY FINANCIAL RIPOFF
By Charles Rhodes

The interruptible electricity financial ripoff is an ongoing forced transfer of wealth from Ontario electricity ratepayers to fossil fuel suppliers. This wealth transfer is a direct result of Ontario government legislation that prevents Ontario electricity ratepayers from using low cost clean interruptible electricity for economic fossil fuel displacement. The interruptible electricity is presently either curtailed (discarded) or is exported at a very low price, typically about $0.02 / kWh. This price occassionally rises to $0.03 / kWh due to intertie congestion, but the average recovery per interruptible kWhe curtailed or exported is less than $0.02 / kWh.

Simultaneously the ratepayers are forced to spend in excess of $1 billion per year replacing the thermal energy content of the discarded low cost clean interruptible electricity ($0.02 / kWh) with much more expensive thermal energy (~ $0.16 / kWh) obtained by combustion of furnace oil, propane and other fossil fuels.

This author believes that this ongoing forced wealth transfer is a result of a very sophisticated sustained fossil fuel lobby in combination with an incompetent and corrupt government and doubts that there will be any electricity ratepayer relief until this matter becomes an Ontario provincial election ballot box issue.
 

INTERRUPTIBLE POWER AND ENERGY:
The Ontario electricity system has sufficient generation and transmission capacity to meet the yearly peak Ontario dependable electricity load plus reserve. The reserve capacity exists to ensure that the dependable electricity load will always be met in spite of unplanned equipment outages. Prior to 2007 most of the available reserve capacity was coal fired electricity generation so at that time there was relatively little available clean interruptible power.

A consequence of replacing coal fired electricity generation with clean (nuclear, hydro, wind and solar) electricity generation was creation of clean interruptible generation capacity which can be used to supply low cost interruptible power. Interruptible power feeds loads under IESO (Independent Electricity System Operator) dispatch control that can be enabled or diabled at any time by the IESO to maintain balance between total generation and total load.

Interruptible energy is the time integral of interruptible power. Generation and transmission of interruptible energy requires negligible extra fuel and no extra equipment. Hence the cost of marginal interruptible energy is very low. The main applications of interruptible energy are for displacement of furnace oil and propane in hybrid stationary heating systems, charging of battery electric vehicles, and for production of electrolytic hydrogen. Interruptible electricity has very limited value in most other applications because it is inherently intermittent.

The interruptible power as a function of time that is presently available in Ontario has been quantified by the Ontario Society of Professional Engineers (OSPE) in a 2017 presentation document titled Ontario's Energy Dilema. In 2017 the amount of available low cost non-fossil interruptible energy in Ontario is about (1 / 7) of total Ontario electricity generation or about 20 TWh / year. This annual amount is projected to decrease during nuclear refurbishment but then increase during subsequent years due to commissioning of additional clean electricity generation.

The dependable electricity rate will sharply increase after 2021 when the "Fair Hydro Rate Plan" discounts expire. The consequent electricity rate increases will likely motivate additional consumer cost cutting via use of interruptible energy. An issue which remains uncertain is the future rate of growth of the Ontario electric vehicle fleet and the impacts of that fleet on grid peak demand, the uninterruptible energy supply and the interruptible energy reserve.

Graph generated by OSPE showing the amount of interruptible power available as a function of time at night during 2016. The available interruptible power is the difference between the green upper line and the purple lower line. The area under the purple line is high value uninterruptible electrical energy. The area between the green line and the purple line is available low cost interruptible electrical energy.

Note that the amount of available interruptible power in Ontario varies over time from zero to about 6000 megawatts. Part of the interruptible power comes from intermittent wind and solar electricity generation and part comes from dependable nuclear and hydraulic generation. Note the decrease in available non-fossil interruptible power in May when nuclear reactors are successively shut down for scheduled maintenance.
 

POTENTIAL COST SAVINGS:
The present misguided Ontario government electricity rate policy prevents use of interruptible power in Ontario. Interruptible power is presently curtailed (discarded) or the corresponding energy is exported at a very low price (~ $0.02 / kWh). In rural Ontario where there is no natural gas service the potential value of interruptible electrical energy for displacement of furnace oil exceeds $.16 / kWh. Hence from the perspective of rural Ontario residents the cost of the present failure to use surplus electricity for displacement of liquid fossil fuels is:

(20 TWh / year) X ($.16 - $0.02) / kWh X (10^9 kWh / TWh) = $3.2 billion / year
 

LEGISLATIVE PROBLEM:
At the heart of the ratepayer ripoff is a faulty implicit assumption, presently enshrined in Ontario legislation, that the cost of delivered electricity should be allocated to electricity consumers in proportion to the number of kWh consumed. For a clean electricity system that assumption is completely wrong. Dependable non-fossil generators and transmitters in Ontario are primarily paid for capacity (kW), not energy (kWh). The cost of dependable clean electricity is proportional to annual peak demand measured in kWe, not the energy generated measured in kWhe. Each consumer's peak demand in kWe can be determined by analysis of that consumer's interval electricity meter data.

The effect of charging a high price per marginal electricity kWh is to cause consumers to use fossil fuel heating instead of electric heating, even at times when surplus electricity is being discarded by the electricity system. This issue causes massive unnecessary fossil fuel consumption in Ontario and causes corresponding unnecessary provincial CO2 emissions.
 

WHO WINS?
Under the existing electricity rate structure the big financial winner is the fossil fuel industry which sells over $1 billion per year of otherwise unnecessary liquid fossil fuel for stationary heating and hydrogen production. Secondary financial winners are out-of-province parties that obtain non-fossil electricity generated in Ontario at a bargain price of ~ $0.02 / kWh and which use that non-fossil electricity to displace more expensive fossil fuels in their own jurisdictions. Both of these financial winners will try to delay implementation of any change in the Ontario electricity rate structure.

Under the existing electricity rate other winners are low load factor electricity customers such as office buildings which have their electricity rates artificially subsidized by higher load factor customers such as high rise residential buildings and 24 hour industries.
 

WHO LOSES?
Under the existing electricity rate structure the big financial losers are the rural Ontario electricity rate payers. Other potential losers are Ontario tax payers who are financially responsible for paying a federal or provincial fossil carbon tax/price on the resulting excess CO2 emissions.

Under the existing electricity rate other losers are high load factor electricity customers such as high rise residential buildings and 24 hour industries that artificially subsidize the electricity costs of lower load factor customers such as office buildings. This unfair electricity rate burden has had an enormous cumulative financial impact on public housing in Ontario such as the 60,000 suites in Toronto operated by the Toronto Community Housing Corporation.
 

ELECTRICITY RATE STRUCTURE FIX:
To fix this situation Ontario provincial legislation must be changed so that the electricity global adjustment, transmission, distribution and regulatory costs are all allocated to electricity consumers in proportion to measured peak demand (kW) instead of in proportion to energy consumption (kWh). Single family residential consumers should be charged about $30.00 / (kW – month) for peak monthly demand calculated over a sliding two hour time window at times when these customers are not receiving interruptible power and should be charged $0.02 / kWh for both interruptible and non-interruptible electrical energy. At times when interruptible power is being supplied the consumer's peak demand calculation should be automatically bypassed. There should be a five year transition period for adoption of the new electricity rate structure. During the initial years adoption of the new electricity rate should be voluntary.

Until electricity rates in Ontario are made primarily proportional to monthly peak demand instead of being primarily proportional to energy consumption it will be financially impossible for electricity consumers to displace fossil fuels with surplus grid supplied non-fossil electricity or to build behind the meter energy storage. Absent this electricity rate structure change most of Ontario's intermittent wind and solar electricity generation will simply go to waste.

The 2017 Ontario Long Term Energy Plan does not contemplate suitably changing the electricity rate structure. The present provincial government prefers to continue giving the fossil fuel industry an ongoing $1 billion per year benefit at the expense of the Ontario electricity rate payers. It is essential that the legislated retail electricity rate structure and the Long Term Energy Plan both be fixed at the earliest possible date.
 

ADDITIONAL INFORMATION:
Persons interested in detail about the interruptible electricity supply should study the OSPE file titled:OSPE Electricity Export Analysis
 

IMPLICATIONS OF AN INTERRUPTIBLE ELECTRICITY RATE:
Assume that the electricity grid is entirely energized by clean electricity generation and that generation and load are matched by use of interruptible load dispatch instead of by generation dispatch.

Assume that there are dependable nuclear and base load hydro generators that operate at power output P. The rate paid to generators for dependable energy is Pp. This generation is never curtailed. Then the amount paid to the dependable generators is:
Integral {P Pp dt}.

Assume that there are intermittent renewable generators that operate at variable power output R. These generators are paid for energy at rate Rp. This generation is never curtailed. Then the cost of this energy is:
Integral {R Rp dt}.

Thus the total cost of generation is:
Integral {P Pp dt} + Integral {R Rp dt}

Assume that there is a time dependent demand D for dependable power. This market pays a premium blended price Dp per kWh. Then the revenue from sale of dependable power is: Integral {D Dp dt}

Assume that there is an interruptible energy market with a very low energy price Ip that can absorb all the interruptible power I that is available for making hydrogen, for electric vehicle charging and for fossil fuel displacement. Then the revenue from interruptible energy is:
Integral {I Ip dt}

Thus the total system revenue is:
Integral {D Dp dt} + Integral {I Ip dt}

For system solvency:
Revenue > Costs
or
Integral {D Dp dt} + Integral {I Ip dt} > Integral {P Pp dt} + Integral {R Rp dt}

Since renewable power is not dependable:
D < P < P + R
which gives:
I = P + R - D

Hence:
Integral {D Dp dt} + Integral {(P + R - D) Ip dt}
> Integral {P Pp dt} + Integral {R Rp dt}
or
Integral {D Dp dt} - Integral {P Pp dt}
> Integral {R Rp dt} - Integral {(P + R - D) Ip dt}

The left hand side is profit from sale of dependable power. The right hand side is loss from interruptible power operations.

For fairness to all parties both the left hand side and the right hand side should approximately equal zero.

In general D varies over time whereas P is nearly constant. Typically the average value of D is:
D ~ 0.7 P
Hence to make the left hand side zero:
Dp ~ Pp / 0.7

To make the right hand side zero:
Integral {R Rp dt} - Integral {(P + R - D) Ip dt} = 0
or
Integral {R Rp dt} - Integral {(0.3 P) + R) Ip dt} = 0

Let Ra be the average value of R

Hence: Ra Rp ~ [(0.3 P) + Ra]Ip
or
Rp / Ip ~ (0.3 P / Ra) + 1

Note that as the average renewable generation power Ra increases with respect to the nuclear generation capacity P the value of renewable generation Rp falls toward the value of interruptible energy Ip.

Typically to compete with natural gas Ip is in the range $0.01 / kWh to $0.02 / kWh.

Note that on a blended energy cost basis the retail price of dependable energy Dp has to be about (Pp / 0.7) where Pp is the price paid to generators for dependable electricity.

If renewable generation supplies 20% of system energy then:
Ra / (Ra + P) = 0.2
or
0.8 Ra = 0.2 P
or
Ra = P / 4

Hence:
(Rp / Ip) = (0.3 P / Ra) + 1
= 1.2 + 1
= 2.2

Summary: If wind and solar provide 20% of system generation and if all the interruptible non-fossil energy can be sold at an average price of $0.01 / kWh then the compensation of wind and solar generators should be $0.022 / kWh less the costs of transmission/distribution caused by the presence of wind and solar generation.

Dependable energy must be sold at a blended price of:
[(cost per kWh of nuclear generation) / 0.7] + costs of transmission/distribution.

Adherence to these price guidelines is required for price consistency and system solvency.
 

This web page last updated January 26, 2022.