PlanetNL50: Hydro Needs More Resources – Why?
The Lies of Muskrat Get a Little Clearer
Two recent news items clue us all into the literally growing mess Hydro has gotten itself to.
One involves the time on people’s digital clocks drifting forward by several minutes – a circumstance few if any have ever seen. It turns out Hydro deviated from the normal precise 60Hz frequency of its AC generation by running at a slightly higher frequency for an extended period of time. This is very unusual and surely didn’t happen without a reason.
The second item is the release of Hydro’s revised Reliability and Resource Adequacy Study last week. The most newsworthy nugget: Hydro says another generating unit should be installed at Bay D’Espoir.
Both items have the same root cause: the inadequacies of the Muskrat project, in particular the Labrador Island Link (LIL) transmission line.
Whatever people may think of Hydro’s past (pre-Muskrat) performance, they should appreciate that at least the operational philosophy of the isolated Island system was stable and well understood. The annual cycle of adding thermal generation at Holyrood for the winter season to supplement on-Island hydro was tried and true from decades of experience.
The addition of a major power infeed via the LIL and a large offtake by the Maritime Link (ML) to Nova Scotia has dramatically changed that picture into something far more complex. Complexity implies there will be a learning curve and discovery of new issues and development of new tactics to deal with them. This would be the case even if the quality of the new systems were excellent. The utility will naturally be expected to act cautiously and try to keep a safety net in place against the highest or worst risks as it goes through this long learning curve.
As Hydro was testing the LIL last month, caution likely dictated that the operators would have more generators on-line than was normally optimal for the load available. Why? Because without the reserve capacity of those extra generators, a sudden trip of the LIL – a very realistic risk during testing – would likely overwhelm all the new control systems and plunge the entire Island grid into the dark.
One side-effect of having extra generation on-line relative to the load is that lightly loaded generators tend to run a little faster than 60Hz. Do that for long enough, as was probably done during the LIL testing, and we can see how simple clocks that depend on AC frequency for keeping time would eventually appear to run a few minutes forward.
Other side-effects of extra light loaded generation must also be considered. There is wear and tear on all those extra energized systems plus there is reduced operating efficiency on them as generators operate most efficiently at or near full power. Utilities ought to avoid doing this.
The worst side effect though is that the utility subsequently develops a case to overbuild its resources because it claims that the higher spinning reserve capacity is a necessity. Ratepayers depend on regulators such as our Public Utilities Bord to ask the right questions to determine if the proposed new capacity is truly necessary and has value to ratepayers.
This brings us to the concept now being proposed by Hydro to build generation unit #8 at Bay D’Espoir (BDE) at a cost estimate of $500 Million. BDE#8 was essentially designed and the sitework partially installed in the 1970s when unit #7 was constructed.
What Hydro is not clearly stating in their new study is that BDE#8 is needed as a band-aid to create spinning reserve power capacity to mitigate the outage risk posed by the LIL. Consistent high frequency operation may be more of a steady thing in the future.
The report also fails to contextualize just how low their view of LIL reliability has become. They did compare the LIL to some other high voltage DC transmission lines elsewhere in the world but those other scenarios involve much larger utility grids that can almost certainly withstand the unexpected loss of any single transmission line.
The relatively large size of the LIL to the small Island system means that if it trips out suddenly, the Island grid will experience a major disruption that risks a complete blackout. The only solution Hydro appears to have found to mitigate this risk is to build out additions to expand reserve capacity that can absorb the impact of such an event.
That’s the simple and direct explanation that Hydro is failing to provide. How they write about the issue in their report is much more roundabout, ostensibly to avoid the heart of the matter.
The reality is that integration of a such a large transmission line as the LIL into the relatively small and isolated Island system is very difficult to manage without having just as much spare capacity in on-Island resources in reserve to instantly replace it. The LIL was a foolish plan, neither technically or economically viable. But now it has been built and we appear stuck with it. Eventually such honesty may prevail but 2022 is apparently too soon.
The report also proves again another Muskrat lie. Holyrood or an equivalent replacement is also needed to provide reserve to mitigate the LIL failure risk. The cost of BDE#8 and an eventual Holyrood replacement represent well in excess of $1 billion of costs that were not included in the original Muskrat budgets. These requirements were entirely foreseeable prior to Muskrat sanction but then Hydro CEO Ed Martin and his many acolytes refused to allow known considerations of good utility practice and design to stand in their way.
Until BDE#8 is built we should expect the Holyrood thermal plant to provide baseload power for the same period of time every winter as it has in recent years in order to maintain the LIL-induced requirement for reserve power. Very modest fuel savings are possible only because the generators will rarely have to run at or near full power.
The LIL therefore does not replace Holyrood. It in fact requires Holyrood to support it to assure grid reliability. Holyrood will therefore supply the lion’s share of winter energy that supposedly the LIL was intended to provide. Nearly all LIL energy will bypass local customers and be shipped direct to Nova Scotia.
As little as 5% maximum of total annual Island energy is likely to be sourced from Muskrat while over 90% of Muskrat energy will be exported beyond the province as Hydro has caught itself in a highly inefficient operational trap.
Even in the Holyrood off-season, it’s doubtful the control systems can react quickly enough to keep the Island grid from failing in the event of an LIL trip. Given the trail of quality issues that has been the story of the LIL to date, there’s plenty of room to be less than optimistic. To be fair we can say that until the systems prove themselves successful, which is likely to take a long time, the utility must reasonably take a cautious approach. Continuing to operate Holyrood in the winter and building BDE#8 soon are the security blanket to maintaining the now acknowledged need for increased reserve capacity year-round.
The issue of increased spinning reserve requirements is an area about which Hydro needs to be more forthcoming; an in-depth study is required. The issue will have a big influence on options for Holyrood replacement as well. It’s quite possible that Hydro don’t yet know how bad it can be until they complete high-power testing and experience the outcomes of high-power LIL trips.
Most utilities select fuel-burning standby turbines as their most viable alternative for seldom used emergency generation. However, if the Holyrood replacement must be on-line and spinning, which now appears fairly certain, then fuel-burning alternatives are not at all attractive.
While BDE#8 has low operating cost, it isn’t an ideal solution because it too has significant risk of transmission failure. The ideal solution must place low or no fuel cost generation near the major load area of concern, the Avalon Peninsula. Lacking major hydro opportunities on or near the Avalon, battery storage is interesting but is far too expensive for anything but very short-term use. As Hydro now indicates, LIL outages must be planned for up to six weeks in duration: battery by itself is not a viable option.
If a major hydrogen industry is developed on the Island, then theoretically it may provide alternatives. Burning expensive hydrogen continuously in combustion turbines to provide instant reserve, however, is far too costly for baseload operation while starting from standby would be far too late to prevent grid collapse. It’s unknown if fuel cell technology at utility power scale could reliably deliver instant full power performance from cold standby: chances are this is speculative technology that does not exist today. There are likely far too many challenges for hydrogen to be an attractive solution.
A combination of proven renewables such as wind, some measure of short-term battery capacity, fuel-fired turbines, and demand reduction programs might be the only viable solution available today. It’s essentially the very same sort of approach that could have been chosen instead of Muskrat and the LIL. It’s quite possible we will have to do all that anyway plus build additional capacity off the Avalon to meet the reserve requirement for the LIL so it can be used almost entirely just to fulfil the 35-year export contract to Nova Scotia.
Hydro cannot yet admit how badly it has painted itself into a corner. The LIL is going to make electricity service on the Island more complicated, more unreliable and more expensive than even the most ardent critics of the Muskrat project have anticipated.
References:
NL Hydro Addresses Clock Jump | VOCM
Board of Commissioners of Public Utilities – see Reliability and Resource Study 2022 update (dated 2022-10-03)
