English (United States)
Columbus, Neb. – NPPD takes pride in using a variety of fuels to generate electricity, including coal, uranium, water, wind, natural gas, and solar. But what about compressed air? Could that be an energy source of the future? NPPD believes it could.
Today, NPPD signed an agreement to purchase certain gas storage leases and related rights from KEBRH Operating, LLC, owner and operator of the Big Springs Gas Storage Unit in Deuel County, Neb. west of Ogallala. The agreement will enable NPPD to test what could be a future, compressed air energy storage facility, if the location proves suitable for such an operation.
Over the next six to eight months, NPPD will develop an air injection, test plan to determine the viability of using the Dakota sandstone formation as a compressed air energy storage facility and energy resource. The plan will determine testing costs, what type of equipment should be used to conduct the test and inject the air, how long will it stay compressed and the rate at which it can be compressed and withdrawn. NPPD expects the test could take 6-12 months to complete.
Information obtained from the air injection test would be used to design a future compressed air energy storage facility, if the project is determined to be beneficial for NPPD and its customers.
In October, NPPD’s board of directors approved negotiating the agreement and developing the test plan. Once complete, the Board will review the projected costs for testing the location’s capabilities as a compressed air storage unit and make a determination about moving forward with the air injection test.
The natural gas storage reservoir was identified by NPPD as a geological formation that could handle sufficient pressure, support the injection of air, and produce good air withdrawal rates. The air would then be used to generate electricity when needed at a later time.
Natural gas is currently stored in the sandstone 3,000 feet below the surface. The sandstone serves as a sponge, storing the gas, most of which has been depleted. KEBRH will continue to remove the remaining recoverable gas from the unit, a process that could take several years to complete.
NPPD will conduct the air test to determine the maximum quantity and pressure of stored air the unit can hold. Neither the size of the compressed air energy storage facility nor the amount of electric production can be determined until this test is complete, but NPPD is hopeful the facility could represent more than 100 megawatts of capacity.
“If feasible as a compressed air energy storage unit, the unit could serve as an alternative energy resource for NPPD’s generation mix,” said Senior Generation Strategies Engineer Mike Matheson. “Electricity from off- peak periods would operate compressors that pump compressed air into the geological formation through injection wells and store it until needed. The air is then withdrawn to serve as the fuel source for powering an air turbine to generate electricity.”
There are currently two, primary, grid-scale technologies used to store energy a) pumped hydro storage and b) compressed air energy storage. NPPD has studied pumped hydro storage, but it is far more expensive compared to the estimated $1,200 - $1,300 per kilowatt in capital costs to construct a compressed air energy facility. In addition, the scale and flexibility of such a resource fits better with NPPD’s system.
“Pursuing this project reflects NPPD’s commitment to studying new energy technologies,” said NPPD President and CEO Pat Pope. “If commercially viable, the facility could benefit NPPD’s in-state ratepayers as an additional generation resource and be one of three, commercial-scale CAES facilities in operation worldwide, joining one in Germany and a second in Macintosh, Ala.”
NPPD is participating in the Electric Power Research Institute Compressed Air Energy Storage Pilot Project. The project is currently being funded by NPPD’s Domestic Energy Research and Application Initiative.
When are rates set?
NPPD rates are reviewed annually, and any proposed rate changes are normally approved during NPPD’s December Board of Directors Meeting.
Will my bill be higher this month because of the cold weather and rolling outages?
Most NPPD customers can expect to see a higher monthly electricity bill this month due to the recent cold weather event which caused customers to have higher usage. A higher bill would not be the result of a rate increase however because the rates did not change.
Does my NPPD rate change throughout the year?
When proposing a rate change, NPPD typically sets and approves rates during the December Board of Directors Meeting. The rates that are approved go into effect February 1 of the next year.
The only other time NPPD’s rates change during the year is when the higher summer rates automatically go into effect for the months of June through September. Aside from this, any increase or decrease in your bill is likely tied to increased energy usage during severe cold or hot weather.
NPPD retail rates have remained steady with no overall increase in eight years.
How will February’s cold temperatures and rolling outages impact my rates in future years?
The financial impact of the most recent historic polar vortex events as it relates to rates are unclear at the present time. Many factors, including future weather impacts, load growth, and the cost to generate and deliver electricity will impact NPPD’s financial position and rates.
How will cold temperatures and rolling outages impact my monthly bill?
Simply put, if you use more electricity than “normal” you will have a higher bill. Rates have not changed. Think of it as a consistently priced fuel, that never fluctuates in price per gallon. If you need to fill up more often, it will require a larger amount of product, and as a result you have higher costs.
Does it take more energy and cost more to lower my thermostat now, only to raise it later to regain warmth?
This is a myth that many have heard for years. Contrary to belief, your system will operate for longer periods to recover and heat pump systems may switch to supplemental or auxiliary heat, but overall energy use is reduced if the setback occurs over at least a few hours.
NPPD operators at our control center handle increases and decreases in load and train for these situations. The operators refer to this as the Cold Load Effect. When customers are returned to service from a long outage, there can be a sharp increase in electricity usage that must be accounted for. As motors begin to start when the load is energized and more equipment powers on than was previously when the customer was interrupted. This means, when there are several customers experiencing an outage at the same time, operators need to consider the load when the circuit is restored can be higher than when it was interrupted. The longer a circuit is interrupted, the more pronounced the Cold Load Effect will be.
In the case of this most recent event, homes were using heat so consistently during the day and the interruptions were short enough that there was no significant change in electricity usage when one circuit was brought back online and another was turned off. During the rolling blackouts, when one group of customers was experiencing an outage, a new set of customers would betaken offline before the first group was returned to service. This helped ensure that there were no spikes in electricity usage that would have a negative impact on the generation and load balance.
Who can I contact for assistance with payment arrangements for my NPPD bill, or information on assistance agencies?
Payment arrangements can be arranged by contacting NPPD at 1-877-ASK-NPPD.
Those in need should also contact NPPD at the above listed number for more information and a listing of energy assistance from local agencies.
What is a rolling blackout outage?
Rolling blackouts, also known as rotating outages, are controlled, temporary interruptions of the electrical service directed by the Southwest Power Pool (SPP). These outages can occur when electricity generating resources cannot meet the electricity demand in the region. NPPD and others must reduce demand in an amount directed by SPP and act upon this within minutes.
When is a rolling blackout necessary?
Rolling blackouts are necessary as a last resort to maintain the reliability of the electrical grid system. SPP directs rotating outages when electricity generating resources cannot meet the electrical demand in the region. They rotate or roll to different systems and areas so we can all absorb a short outage at different times versus a long outage for one specific area.
The recent situation was extraordinary and an unprecedented chain of events, including historic low temperatures across the entire SPP footprint, lack of wind generation, reduced amounts of natural gas because of frozen wells and sky rocking natural gas prices. A situation never seen before in this region since SPP was founded.
Why was there little notice before power was shut off to some customers?
Just like many of our retail and wholesale customers, NPPD received the emergency notices from SPP with little warning, requiring us to load shed with just a few minutes to act.
NPPD did our best in this emergent situation to communicate not only to our large industrial and residential retail customers, but also with as many wholesale customers as we could. This was done with a press release, via emails, regularly scheduled wholesale customer meetings throughout the event, and using social media. Unfortunately, with the short timeframe not all customers were able to be reached before some outages began.
We continue to evaluate and review the events of this situation and will look for ways to learn and improve our process, should it ever be needed again.
Is there an easy way to track my energy usage?
Tracking your energy usage can easily be done by downloading NPPD’s mobile application, “NPPD On The Go!”. Download by searching “NPPD” in the Google Play or Apple App store. Then click “Register” and have your account number, service address zip code, and phone number ready. Finally complete the account information.
What are the benefits of using “NPPD On The Go!”?
Who and what is Southwest Power Pool (SPP)?
NPPD is a member of the Southwest Power Pool (SPP), a non-profit regional transmission organization in the central part of the United States. SPP is mandated by the Federal Energy Regulatory Commission to ensure customers in the region receive reliable power, adequate transmission infrastructure and competitively priced electricity. SPP and its members coordinate the flow of electricity across more than 65,000 miles of high-voltage transmission lines spanning 14 states.
Why is it important to have a diverse energy mix?
NPPD believes a diverse generation mix serves our customers best. We use wind -- when it is available. We use coal -- which is reliable and helps keep electric rates low. We use water -- one of the oldest forms of renewable energy. We use nuclear -- which offers emission-free, around-the-clock power. We use natural gas -- to complement the portfolio.
NPPD’s diverse energy generation mix helps keep our electricity reliable and keep rates as low as possible.
Public power, as it always does, answered the call to help protect the bulk electric system which serves the central portion of the country and is part of the larger Eastern Interconnect. The system requires real-time balancing of generation and load. In doing so, we also protected our customers from more detrimental, long-term blackouts.
All of NPPD’s plants were available to SPP during this emergency event. They performed as beautifully during the emergency as our NPPD teammates who worked around the clock to manage the safety, health and financial risk for our customers.
