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The Sun for a Penny

I recently presented at the Canadian Electricity Association (CEA) on the future of the industry.

What would happen to the power industry if the cost to generate solar electricity reached 1¢/kWh? What could be the impact of a carbon tax? What are the business opportunities arising from the need for reliable power?

While electric utilities have seen tremendous transitions during the 125-year history of the CEA, the current rate of development is unprecedented. To paraphrase a famous quote by Wayne Gretzky, utilities need to “skate to where the puck is going to be, not where it has been.” This presentation tried to provide power utilities with some insights into the future direction of the puck!

See the presentation here: The Sun for a Penny 20170225a

The New Grid Needs to Be a Lot More Complicated

The Old Grid used to be relatively simple, with generation following load:

Old Grid

It is now a lot more complicated:

New Grid

The grid is transforming and getting more complicated.

  • We are decommissioning fossil plants to reduce GHG emission and nuclear plants because of safety concerns.
  • There is only so many rivers, so the solution of building new hydro plants is not sufficient.
  • We are then replacing fossil and nuclear base load plants with renewables that are intermittent.
  • To compound the problem of balancing the grid, loads are also becoming peakier, with reduced load factor. Interestingly, many energy conservation initiatives actually increase power peaks.
  • To connect the new renewable generation, we then need to build more transmission. The transmission network also allows network operators to spread generation and load over more customers – geographic spread helps smooth out generation and load.
  • Building new transmission lines face local opposition and takes a decade. The only other alternatives to balance the grid are storage … and Demand Management.
  • Another issue is that we are far more dependent on the grid that we used to be. With electrical cars, an outage during the night may mean that you can’t go to work in the morning. So, we see more and more attention to resiliency, with faster distribution restoration using networked distribution feeders as well as microgrids for critical loads during sustained outages.
  • Renewable generation and storage can more effectively be distributed to the distribution network, although small scale generation and storage are much more expansive than community generation and storage.
  • With distributed generation, distributed storage and a networked distribution grid, energy flow on the distribution grid becomes two-way. This requires additional investments into the distribution grid and a new attention to electrical protection (remember the screwdriver).

All of this costs money and forces the utilities to adopt new technologies at a pace that has not been seen in a hundred years. The new technology is expensive, and renewable generation, combined with the cost of storage, increases energy costs. There is increasing attention to reduction of operating costs and optimization of assets.

“Resilient Power for Sustainable Cities” Presentation at the Canadian Electricity Association

I presented this to senior managers of Canadian utilities attending the 24 February Distribution Council of the Canadian Electricity Association. It can be found on SlideShare at http://www.slideshare.net/bmarcoux/resilient-power-for-sustainable-cities.

Abstract

The cost of disasters has been increasing exponentially since the 1970s – and cities are mostly affected, which is not surprising since cities produce 80% of the world gross domestic product (GDP). Since the majority of disasters are related to climate events, cities are also part of the root cause, since they generate 75% of our greenhouse gas (GHG) emissions. Mayors, acting locally on a short feedback loop, view the challenges they face on a daily basis – it is about their constituents getting sick, having clean water, being warm or cool, holding productive jobs, commuting efficiently, surviving disasters. They see that a smart city needs, first and foremost, to be both resilient to face increasing disasters and sustainable to reduce its environmental impact and to improve quality of life – while being financially affordable

Cities can’t function without electricity. It moves subways and trains. It cools, heats and lights our homes and businesses. It pumps our water and keeps fresh the food we eat. And it powers the technologies that are the foundation of a smart city. By implementing smart grid technologies such as microgrids and distribution automation, electric utilities play a key role in making cities both resilient and sustainable. Yet, many electric utilities do not partner with mayors to work on cities’ resiliency and sustainability challenges. A better approach is to see city policy makers as major stakeholders and a driving force in modernizing the grid.

Have you talked to your mayor(s) lately?

GTM Squared Report

I just finished reading the annual survey of utilities prepared by GTM Squared (http://www.greentechmedia.com/squared/read/annual-survey-report-2016-the-future-of-global-electricity-systems). I found it a useful reference to understand the challenges faced by utilities worldwide, and I thought of sharing some interesting highlights:

  • 3/4 of utilities say that regulatory hurdles are the greatest challenge they face today. Preference is to develop market-based reforms, as well as clear interconnection/net metering rules – in other words, mechanisms that deal with/assign value to Distributed Energy Resources. Note that DER (such as distributed generators and storage) will play an increasing role in utilities worldwide.
  • Half of respondents see the consumers at the forefront of the industry’s evolution. However, it is surprising that utilities in the same survey do not put a greater priority on customer engagement.
  • On storage, respondents see an increasing emphasis toward actual projects, and less on the physics and technology of storage. DER vendors now offer better systems intelligence and grid integration to companies focused on building a next-generation power grid (more sustainable and more resilient). Energy storage is now living up to the hype, having seen record installations in 2015.

Utility-Scale Solar Report

I finally got around to read the US Department of Energy report on utility-scale solar energy (https://emp.lbl.gov/sites/all/files/lbnl-1000917.pdf) published a couple of months ago. Here are my highlights:

  • Installation trend is compelling. Installed capacity is now 30,000 MW – about 30 times more than 5 years ago.
  • Installation costs are falling – by more than 50% since the 2007-2009 period, the lowest-priced projects being around $2/W (AC).
  • Capacity factor is now improved to 27.5%. The main factors of this variation are, in order of importance: the strength of the solar resource at the project site; whether the array is mounted at a fixed tilt or on a tracking mechanism; the inverter loading ratio; and the type of PV modules used.
  • Power purchase agreement prices have fallen. Utility scale solar PPA is now as low as $40/MWh. At these low levels – which appear to be robust, given the strong response to recent utility solicitations – PV compares favorably to just the fuel costs (i.e., ignoring fixed capital costs) of natural gas-fired generation, and can therefore potentially serve as a “fuel saver” alongside existing gas-fired generation (and can also provide a hedge against possible future increases in fuel prices).

Evolution of Energy Generation and Distribution in Canada’s Smart Power Grid – Innovation 360 Conference Panel

On September 29, I was asked to participate on a panel titled “Evolution of Energy Generation and Distribution in Canada’s Smart Power Grid” at the Innovation 360 conference in Gatineau, Québec (http://innovation360.ca). Here is the essence of what I contributed.

By definition, in an electricity network, energy consumption plus losses equal electricity generation. This must be true at any point in time, or protection systems will shed load or trip generators.

There are 4 ways to balance load and generation:

1) Traditionally, dispatchable generators that can easily ramp up or down were tasked to follow the load. Big hydro plants and natural gas generators are particularly good at this. However, we are running of big hydro opportunities, and natural gas are sources of greenhouse gas emission, contributing to global warming.

2) Another way to balance load and generation is to interconnect with neighboring network that may not have the same load profile. Today, all of North America is interconnected in some way. However, building transmission lines is a lengthy process that typically faces major local opposition. As a result, most transmission lines run at capacity during peaks, weakening the bulk transmission system as the Northeast blackout of 2003 demonstrated.

3) In the last couple of decades, we have started to control load, like turning off air conditioning units by pager or getting large industrial like smelters to go offline for a couple of hours during a major peak. Time-of-use or market pricing are also attempts to have loads better follow available generation capacity. However, much of the conservation focus thus far has been on energy efficiency, not peak load reduction.

4) Very recently, energy storage has been getting attention. Traditionally, the only utility-scale storage technology available was pump-storage, like the Sir Adam Beck plant in Niagara, but few of those plants are possible, and they are not efficient. Going forward, batteries, either utility-scale or distributed storage, will grow, although for now utility-scale batteries are MW-class, when hundreds of MW or GW are needed.

Balancing load and generation is also becoming more and more difficult. On one hand, consumption is getting peakier, partly due to side effects of some energy saving programs, like turning down thermostats at night in the winter, and then turning them back up in early morning, just in time for the morning peak. On the other hand, wind and solar generators are replacing fossil generators, adding unpredictability to generation and taking away controllability, thus requiring even more balancing resources.

Integrating renewable into the grid is not only causing balancing problems. It also creates voltage management and protection problems. Those are solvable, but significant, engineering problems that require expensive upgrades to the electricity grid.

Ultimately, load and generation balancing, voltage management and grid protection adds costs that are ultimately born by subscribers. It therefore quickly becomes a political issue.

As a society, we have been subsidizing fossil fuels. Clearly, going forward, we will need to greatly invest in the grid if we want to limit the predicaments of global warming for our children and grand-children.

Using Analytics to Assess Station Thermal Risks Caused by Reverse Power Flow

With sufficient Distributed Generation (DG – embedded generation in Europe) installed on the feeders of a substation, reverse power flow may occur at the station when load is low. This is especially the case when large generators (such as wind farms) are connected on express feeders dedicated to their use.

Substations have been designed, rated and operated as step-down substation with power flowing from higher system voltage to lower system voltage. Some substation transformers also have dual secondary winding transformers that do not allow for reverse power flow conditions, as unequal reverse flow in the two secondary windings would cause overheating and potential failure of the transformer.

Utilities limit DG capacity downstream of a station to avoid excessive reverse-flow and to prevent overheating of substation transformers. For example, Hydro One requires that generation shall not exceed 60% of the maximum MVA rating of a single transformer plus minimum station load.

The (worst-case) engineering assumption is that maximum generation coincides with lowest load at a station. Is it the case? Some years ago, I ran a Monte-Carlo simulation between load and wind generation, based on theoretical distribution of both, but doubling the generation normally allowed. It found that generation would be excessive… less than 2% of the time (and not by much, and at a time when load is low and so are prices). Using actual smart meter data, it is now possible to actually know what is going on and better assess risks. For solar generation in hot climates, there is a negative correlation between load and generation – in other words, maximum generation does not happen in times of minimum load.

Even better: correlating with forecast weather data can assess whether reverse flow could be excessive in a few hours, and require large DGs to go off-line ahead of a problem (and this would not happen frequently). While I have not seen such an application, it is clearly in the realm of possibilities.

Deep analytics, used as a planning tool or in support of operations, enables safe integration of more distributed integration by managing thermal limit of station transformers operating in reverse flow.

Tutorial: Key Players in the Energy Markets: Rivalry in the Middle

The players described in the previous post have vastly different characteristics. The most striking difference is the level of rivalry.

IMG_2174

Distributors operate in a defined territory, often corresponding to a city, a state or a province, where they are the sole provider – thankfully, as there would otherwise be multiple lines of poles along roads. Given this monopoly, distributors are subjected to price regulation, meaning that the price they charge for the use of their infrastructure (poles, conductors, cables, transformers, switches, etc.) is set, typically equal to their costs plus an allowed return on their investment. This is done by filing tariffs that are approved by the regulatory body following a rate hearing.

Retail is often a competitive industry, as there is no structural barrier to having multiple players. However, some distributors are also given the retail monopoly over their territory. Some may also provide retail services in competition with other retailers. In those cases, the distributor-owned retailer is also regulated and has to seek approval of its rates, but other retailers typically do not, although they may have to file their rate plans.

It is possible to have multiple transmission companies operating in the same territory, each owing one or a few transmission lines. However, because those transmission lines are not perfect substitutes (they do not necessarily have the same end-points in the network) and because transmission capacity is scarce, electricity transmitter typically have regulated rates, although they may compete for new constructions.

System operators are monopolies over a territory, and they have to maintain independence. They are, in effect, monopolies, although system operators are often government- or industry-owned. Their costs are recharged to the customer base, directly or indirectly.

Large generators are in a competitive business, competing in an open market, although distributed generators, which are much smaller, usually benefits from rates set by a regulator or a government.

Tutorial: Key Players in the Energy Markets

I will be making a conference to investors later this year and I will also be training some people internally at my employer. The topics will touch on the electricity industry structure and I am preparing some material for it.

The industry can be quite complex in some jurisdictions. I boiled the complexity down to just this:

New Picture

Traditional large-scale generator own and maintain coal, natural gas, nuclear, hydro, wind and solar plants connected to transmission lines. Those are large plants – typically hundreds of megawatts.

Transmitters own and maintain transmission lines – the large steel towers seen going from large generators to cities. Those typically run at 120,000 volts and more, up to over 1,000,000 volts in some cases.

Distributors own and maintain the local infrastructure of poles and conduits going to customer sites. Those typically run at 1,200 to 70,000 volts, usually stepped down to 600 volts. 480 volts, 240 volts or 120 volts for connection to customers.

Most customers are connected to distributors, although some large industrial facilities (such as aluminum smelters) are directly connected to transmission lines.

While customers are connected to distributors, they purchase electricity from an independent retailer or from the retail arm of a distributor.

With customer installing distributed generation on their premises, they sell back power to the market, often through aggregators.

Retailers buy electricity from generators in an energy market – like a stock exchange, but for electricity.

By definition, the energy produced at any instant must be equal to the energy taken by customers, accounting for a small percentage of losses in transmission and distribution. (We are starting to see large-scale storage operators, which may act as both consumer and generator, depending they are charging or releasing electricity in the network.) This critical balance is maintained by the system operator that direct generators to produce more ore less to match load; in some case, the system operator will also direct distributors to shed load (customers) if generation or transmission is insufficient to meet the demand.

The next post will deal with energy and money flows in the market.

Covered Conductors Vs. Single-Phase Reclosers

A utility client told me that they were trying out covered conductors on a feeder in a forested area. This was the first time that this large utility tried covered conductors. The objective is to reduce the impact of tree contacts and falling branches that blow fuses and therefore result in permanent outages for customers. In this context, the great length of feeders and the high system voltage (25 kV) make coordinating reclosers and fuses difficult.

Covered conductors have a thin insulation covering – not rated for the full phase voltage, but sufficient to reduce the risks of flashovers and fire when a tree branch falls between phases, when a tree makes momentary contact with a conductor, or when an animal jumps to it. Covered conductors also allow utilities to use tighter spacing between conductors.

While covered conductors help with tree contacts, they also have a number of operational disadvantages:

  • High impedance faults with a downed conductor are more likely, leading to public safety issues, especially since the conductor may not show arcing and may not look as if it is energized.
  • Covered conductors are more susceptible to burndowns caused by fault arcing. Covering prevents the arc from motoring with magnetic forces along the wire, concentrating heat damage. Repair time and cost increase significantly.
  • Covered wires have a larger diameter and are heavier, increasing loading, especially with freezing ice and high wind, which can likeliness of mechanical damages (including broken poles and cross arms), leading again to high repair time and costs.
  • Covered conductors have somewhat lower ampacity at high temperature (worsened by the black color that absorb more heat from the sun), with more limited short-circuit capability. High temperature also degrades the insulation. This results in more design and planning constraints that may increase construction costs.
  • Water can accumulate between insulation and wire at the low point between of a span, causing premature corrosion and weaken the conductor and can lead to failure.
  • Covered conductors must be installed differently than bare ones. For instance, using conducting insulator tie can lead to partial discharges and radio interference.
  • Finally, cost is an obvious issue – replacing conductors on existing lines is extremely expensive, possibly as much as $100k per km.

These issues got me thinking on how I could provide a better alternative. Replacing fuses with single-phase reclosers appears to be an interesting (if unlikely) alternative to covered conductors. Cutout-mounted single-phase reclosers can easily be installed in existing cutouts to protect lateral circuits. Those circuits are then protected against tree contacts without the disadvantage of covered conductors. Coordination with upstream mainline reclosers is eased by making the single-phase recloser faster than the mainline recloser. Cost is clearly lower than re-conductoring.

Full disclosure: I am employed by S&C, and S&C makes a cutout-mounted recloser.