Frankly Peaking: Transmission Integration of Wind and Solar

Guest Blog | June 18, 2012 | Energy Policy

In the Southeast, we dream of a power system largely supplied by renewable energy generation and storage, the kind that is being introduced in other regions of the United States. Up to now, we have heard from our utilities that while they recognize that our region has ample wind and solar potential and that they would like to accommodate it, they just really can’t — sadly, their transmission systems are not designed to introduce wind and solar because they peak in the middle of the day and later in the evening (thankfully they at least coincide with peak demand). To clarify, utilities admit that their antiquated transmission systems are not capable of reliably providing for incremental additions at strategically congested transmission locations and that it is very expensive for them to acquire the knowledge or technology to schedule wind and solar resources because they are intermittent, non-firm resources. Boy, will they ever be pleased to learn from the experts at the recent American Wind Energy Association Annual Conference in Atlanta that transmission technology has now advanced to the point that the transition from dirty burning coal and risky nuclear to wind and solar is not only possible but it even enhances reliability.  It would appear as if even our Southeastern utilities would be able to make our dream come true!

Let’s be frank — other forms of generation have peaking issues too

While wind and solar integration costs may increase the variability and uncertainty that must be managed on the power system, there are plenty of other sources of variability. The performance of coal and gas plants, for instance, the ramping and cycling of these units and the very low capacity factor of some coal units – not to mention the fact that when nuclear units go off line, it is unfortunately due to critical and high risk problems that don’t ever seem to be resolved either on schedule or within budget.  Simply put, Michael Milligan of the National Renewable Energy Laboratory, said in his presentation that integration costs are not unique to wind or solar and should perhaps instead be assessed by other factors such as power plant performance instead of technology type.

Wind and solar actually increase efficiency and reliability

Dulan Weeasinghe of Kansas State indicated that maximizing distributed generation and storage is really a matter of sizing and siting for wind and solar. If properly done, the introduction of 20-30% renewables in a generation mix would still enable total system functionality. It actually has the effect of increasing efficiency and reliability.  Accompanied by distributed storage, it serves to smooth up all generation and help decrease peak load demand.  It is just a matter of finding the initial placement while considering the voltage profile of the system and satisfying the rest from conventional generation.  To this end, multinational power technology provider ABB highlighted a range of services it can now provide at the junction of operations technology (OT) and information technology (IT) through Ventyx, its recently acquired IT partner. ABB is now is now able to forecast load and resources, siting, and valuation and integration of renewables, leading to a grid capable of including more wind and other renewables.

Southeastern utilities can learn from the vast experience of other regions

Fortunately for us in the Southeast, we have ample experience of others to go by.  MISO (Midwest Independent System Operator) recently developed Multi-Value Projects (MVPs) to address reliability, economic, and policy needs. They address congestion on the transmission system, reliability constraints, and clean energy additions. According to MISO, the 17 approved Multi-Value Projects (collectively, the MVP portfolio) will provide economic benefits exceeding their costs, and will enable the delivery of at least an additional 41 million megawatt-hours (MWh) of wind energy per year. PJM, the largest independent system operator in the United States, details in their 2011 State of the Market, how energy market forces in their system are retiring coal power plants, encouraging renewable energy generation, and stimulating demand response while reducing consumer electricity costs.

Low wind prices do speak to utilities

Wind power prices dipped low enough to compel the Tennessee Valley Authority to contract for 1,535 MW of wind or 4.3% of its total generation of 35,000 MW.  The expectation is for TVA to phase in more wind energy over time as Clean Line and Pattern Energy plan to develop transmission projects that will bring an additional 8,500 MW of wind energy to our region.

With demand down and revenues lower than expected for most utilities in the Southeast, it sure is difficult to justify expensive new nuclear plants in light of these revelations.  It should give us all pause for reflection.  Now that we know wind and solar no longer have to suffer technical barriers of unduly burdening transmission, we can invest in generation that poses no risk to our health and continued existence on this planet.

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