This Distributed Energy Resources White Paper presents a high level look at New Zealand’s current power grid systems architecture in the wake of the damage this infrastructure has received during recent extreme weather events, such as Cyclone Gabrielle, and how we can shift the way we build back damaged infrastructure to take advantage of Distributed Energy Resources to provide greater power resiliency for New Zealand homes and businesses.
This is the web version of the Distributed Energy Resources White Paper. Download the PDF version here:
New Zealand has an aggressive decarbonisation goal of 100% renewable electricity by 2030, and carbon neutral by 2050. New Zealand needs more generation capacity, but additional capacity will likely need to be decentralised and intermittent, rather than centralised and firm. As the capacity of intermittent generation increases, the dynamics of electricity supply going forward for both customers and the grid must change to maintain a secure and reliable supply of electricity. We need to adapt to new methods of operation to minimise electricity delivery costs, create a reliable, renewable, electricity supply and defer wider grid upgrades.
As decarbonisation has increased electrical demand, there is already growing evidence of lack of generation capacity and reserve at peak times when it is most needed. This is not a new issue, but in New Zealand has been growing over time. It indicates potential issues within a competitive energy only electricity market. Our competitive energy only electricity market has served the country well, but a high intermittent mix of electricity generation will not work under the current electricity market structure without imposing significant delivery cost on consumers. Growing congestion issues with connections between electricity generation and demand are occurring as we transition to a greater capacity of intermittent decentralised electricity generation.
A solution is needed before problems occur, and it is available now. Distributed energy response in the form of batteries, demand control, microgrids, distribution system operators and localised generation is here now. If you run critical electricity plant, you need to consider what your cost is if electricity supply fails, against the alternatives available to you now. An event occurring is not the time to seek alternatives as everyone else will be doing the same. It will be too late to prevent economic harm to investors on both sides of the meter with potentially stranded investment.
So why is the centralised nature of our power grid an issue, and how does implementing a more decentralised approach to national energy resources improve our ability to respond to issues on our power grid, and how can we cope with intermittent generation that may add significant volatility to wholesale electricity market cost? The answer is smart grids. As electricity generation is decentralised, control must also be decentralised, and storage must be added to the electricity supply system to ride out the intermittent generation troughs which will occur when wholesale pricing will be the highest.
2 Our Current Centralised System
Cyclone Gabrielle has brought New Zealand’s power grid to its knees. It could have been worse if the cyclone or any similar disaster damaged significant capacity of electricity generation. If that were the case, there could have been national issues on meeting demand (particularly in dry years) and wholesale electricity market cost would have escalated markedly.
The current issues facing New Zealand’s national power grid in providing power to communities affected by Cyclone Gabrielle are not isolated to only during emergency conditions, the current lack of peaking winter reserve generation is further evidence that we have significant electricity supply issues. The extra stress put on the system by the extreme weather event simply allowed us to identify what was working and what was limping along.
Those systems that failed during the cyclone were not suitable for use in extreme events long before the cyclone occurred. Those systems that failed were prone to failure, it was just not evident until the electricity supply system became stressed.
The extra stress put on the electricity supply system gave us an early look at how the system, as it exists now, will be able to handle decarbonisation with increasing electricity demand in an uncontrolled manner. It is unfortunate that it took a cyclone to shows us what happens when a part of the current mode of systems architecture and operation has too much burden placed on it. It fails, causing massive personal and economic damage.
Our current mode of systems architecture for the power grid prioritises interconnectivity. This does have its advantages, but under stress it also needs infrastructure that enables peak demand to be managed to ensure that electricity available can be provided for critical uses.
Historically, electricity has been more economic and more efficient and reliable to generate at centralised large-scale electricity generation stations, and electricity reserves have been more economic at grid scale through fast acting hydro generation. This is changing as it is becoming significantly more difficult to consent and build centralised electricity generation, and more economic to build intermittent decentralised electricity generation, and technology is now available that enables effective distributed energy response.
Through extensive interconnectivity both centralised electricity generation and intermittent decentralised electricity generation can be used to power communities all over New Zealand. But that close interconnectivity is our current electricity infrastructure’s main weakness. It is a network of dominoes, and no matter how much you reinforce each domino all it takes is one to fall and start a chain reaction. Many supply interruptions are caused by entirely avoidable problems somewhere in the electricity supply system. Once one part of the electricity supply system goes down, rerouting electricity through other parts increases the likelihood of power loss in surrounding locations.
Centralised generation and distribution have required us to implement an extensive network of lines, connections, and distribution hubs that have now resulted in restrictive bottlenecks and congestion at the best of times and the potential for complete outages at the worst. Every kilometre of lines is a kilometre that electricity has to travel through and kilometres that can fail causing end users to lose electricity supply.
When electricity supply fails, there is little that the current infrastructure can deliver in terms of backup supply locally. When our grid needs additional electricity, our current infrastructure architecture meets demand through increased central generation dispatch, but this assumes the electricity grid is in working condition and with enough capacity to get the additional generation to where there is consumption. It is a one-dimensional system, where we try to ensure that we always have enough generation available to cover our electricity demand plus a contingent risk but does not include consideration of continuity of the grid in the event of disaster.
The grid could partially fail, limiting electricity supply, but there could still be adequate decentralised electricity generation available within networks to supply isolated sections. This would take the form of microgrids that can work in isolation from the grid or networks where there is sufficient distributed electricity generation within the constricted area to supply consumer’s essential load. But the infrastructure at the moment only provides for the coordination and dispatch of generation above 30MW, and then only for a country wide dispatch process. Distribution system operator methodologies, coupled with distributed energy response, demand reduction, and remote network switching could manage electricity supply at the localised level.
3 How to Mitigate These Issues
So how do we stop looking at the problem of grid resiliency one-dimensionally and begin building a system that can stand up to the issues we have seen over the last few weeks? Here are two key recommendations:
- Do not rebuild like for like what was destroyed. There are new technologies and innovative alternatives that can deliver ongoing consumer benefit. This includes non-network options, such as renewable energy microgrids, community and grid battery storage, distribution system operators, more self-sufficiency, adequate voltage and thermal capacity for EV charging, in-home generation and storage, new methods of consumer transactions to encourage self-sustainability, and smart houses;
- Do not throw out the existing infrastructure that is not being replaced, but instead build on top of it to provide similar functionality to the above.
This is the era of Smart Grids. As with all systems design, the prioritisation of certain aspects will mean that current design methodologies fall by the wayside. Smart Grid design can include multiple system architectures that are overlapping to meet different priorities and cover each other’s failure points, so that when stress is placed on the grid, only those systems susceptible to that type of stress fail, and those systems that remain are able to re-mesh to maintain supply to critical load while issues are being fixed.
The overlapping of these multiple system architectures and methodologies allows us to implement a new decentralised approach to New Zealand’s power grid that meets both of these key recommendations. It utilises new technologies and innovations rather than simply building back what was already there, while also making the most of the existing infrastructure by supporting the existing equipment rather than requiring it to be completely replaced.
4 Decentralising Our Current System
So, what systems can be placed alongside the existing large-scale generation and transmission systems as a part of these multiple overlapping systems? The core issue with the existing infrastructure is, the inability to supply power close to demand, meaning that in the event of a localised failure, electricity supply is not available past the point of failure even though the downstream infrastructure was still uncompromised. We take providing this capability as the basis for our additions to the grid’s infrastructure. Systems need to be provided to enable the co-ordination of locally generated electricity and reduce customer demand where needed.
Decentralising our current electricity system involves an energy transition, shifting away from centralised large-scale generation stations and transmission lines towards a more distributed system where electricity is generated and consumed locally. This can be achieved through various means, including the use of renewable energy sources, microgrids, and energy storage. It is also important to consider policy and regulatory frameworks that encourage and support this transition. Regulators have a key role in amending regulation to remove barriers and provide incentives for the adoption of renewable energy and energy storage systems, promoting innovation and research in decentralised energy systems, and establishing new market structures that allow for the integration of distributed resources into the grid.
Decentralising our current electricity system has the potential to increase energy independence, reduce greenhouse gas emissions, and improve the resilience and reliability of our electricity infrastructure.
One approach to address the issue of supplying electricity close to the point of consumption is to implement distributed energy resources (DERs) such as solar panels, wind turbines, and energy storage systems. These systems can be installed at or near the point of consumption, reducing the distance between generation and consumption and increasing the reliability of the electricity supply.
- Smart grids can also be implemented to enable the coordination of locally generated electricity and balance customer demand. Smart grids utilize advanced technologies such as sensors, communication networks, and automated control systems to gather and analyse data on electricity supply and demand, and adjust generation and consumption in real-time to maintain system stability.
- Implement sustainable microgrids, which are self-contained electrical systems that can operate independently or in parallel with the main grid. Microgrids can be connected to the main grid to supply excess power or to receive power during times of low generation, and can also operate independently during power outages or other grid disturbances.
- Demand response programs can be implemented to incentivise customers to reduce their electricity consumption during peak demand periods, thereby reducing strain on the grid and improving system reliability.
Overall, a combination of these systems can be implemented alongside the existing large-scale generation and transmission systems to create a more resilient and reliable grid infrastructure.
Standby electricity generation in the form of diesel engines has traditionally been provided by customers on their own premises to enable critical consumption to continue where the grid connection has failed or cannot meet the consumers peak power demand. This solution can solve the issue in a small, localised manner. It is suitable for an individual premises with critical load as a final backup to failure but is not suitable at a community wide level as the plant is usually only dedicated to total electricity supply failure. It does not provide all of the benefits that it could under increasing intermittent generation scenarios.
There are also environmental impacts to consider. In the face of an emergency like we have seen in Cyclone Garbrielle, getting electricity back online across the region by emitting tons of greenhouse gases can feel like robbing Peter to pay Paul. But this does give us a look at what we want out of our power grid’s supplementary systems. We want distributed systems that generate close to the end user, but also serve as energy reservoirs, waiting and ready to go when needed.
There are a variety of assets that can fill the function needed for generation and storage. Microturbines and small-scale wind farms, small-scale hydroelectric generation, solar panel arrays, or battery energy storage systems can provide power at the scale required whether operated by end users or utilities. These distributed energy resources can provide supply locally when centralised supply is cut off or congested. They can respond to local demand more dynamically than centralised resources, providing power to supplement utilities and industrial sites with large electric loads during standard operating conditions without imposing additional load on the grid, while providing backup power to the immediate area during a crisis even while wider distribution and transmission assets are down.
The two systems can work together, with the strengths of both covering each other’s weaknesses providing resilience and flexibility. The use of decentralised electricity generation and storage, mixed with decentralised control could keep downward pressure on electricity prices and allow load balancing across the whole country, while providing localised peak power and standby supply. Such an operating system could defer capital costs on the grid and within networks, as well as providing true investment price signals to investors.
Resiliency is provided by the overlap of centralised and decentralised resources, rather than trying to make one system do it all.
5 Distributed Energy Resources (DER)
DERs are a decentralised energy system that generates or stores energy close to where it will be used. DERs can include a variety of technologies, such as solar panels, wind turbines, energy storage systems (such as batteries), and even small-scale standby or peaking generators such as natural gas or diesel generators and even potential future technologies such as hydrogen fuel cells or engines.
The term “distributed” refers to the fact that these energy resources are located throughout the grid, rather than concentrated in a few large generation stations. DERs can be owned and operated by individuals, businesses, or utilities, and can be integrated into the grid in a variety of ways.
DERs have several advantages over traditional, centralised generation stations. They can improve grid resilience by providing localised backup power during outages or emergencies by islanding either a section of a network, or individual buildings. DERs can also reduce the need for transmission and network infrastructure upgrades as demand on a network increases due to decarbonisation, as electricity can be generated.
However, the integration of DERs into the grid can also pose challenges. Sophisticated control systems may ultimately be needed as there is little difference in impact of a 1 x 30MW generation station, and 1,000 x 30kW smaller user operated generators. If these smaller plants operate in a co-ordinated manner, they are termed a virtual power plant (VPP) and have an impact on grid stability. Dispatch of VPPs is not currently covered by the Electricity Industry Participation Code 2010.
There are various fuel types for DER that can be considered, however without a storage lake, typically DER electricity generation is classed as intermittent. This means electricity generation will occur when the fuel is available. Intermittent generation is dependent on the availability of the fuel such as sunlight or wind speed. If intermittent generation is the only source of electricity available, then the variability of the electricity generation can make it challenging to integrate into the grid, microgrids, businesses, or residences to ensure a consistent supply of electricity. This may be due to voltage profiles and congestion.
To address the challenges of intermittent generation, energy storage technologies, such as batteries and pumped hydro storage, can be used to store excess energy during times of high intermittent electricity production and release it during periods of low production. Additionally, this smoothing can be used to manage and balance the supply and demand of electricity, to ensure there is always electricity available to meet demand through smart grid technologies.
5.1 Solar Generation
Solar generation is perhaps the easiest to implement of all distributed energy resources. Solar panels are easily retrofitted onto existing buildings or integrated into new designs to allow a building to use unutilised space to generate electricity. Also, larger scale solar farms are relatively easy to construct. But there may be difficulty in obtaining land, resource consents and grid connection.
The disadvantage of solar is that without batteries, it will only generate electricity during sunshine hours, and even then, generation varies with the amount of solar radiation on the panels.
5.2 Wind Generation
Wind generation is more consistent in its generation profile than solar, due to its consistency and ability to generate electricity throughout the day and night. Wind turbines can be installed at large scale wind farms as a centralised form of electricity generation, but can also be installed at distributed sites, such as on rooftops or in remote areas, to provide electricity for local use. Larger scale wind farms are relatively easy to construct, but again there may be difficulties in obtaining land, resource consents and grid connection.
The disadvantage of wind is that without batteries, it will only generate electricity when the wind blows, and even then, generation varies with the amount of wind.
5.3 Hydroelectric Generation
While typically used at a large scale here in New Zealand , hydroelectric power can be generated on a variety of scales, from large-scale dams to small-scale run-of-the-river projects. Small-scale hydroelectric projects typically involve diverting a portion of a river’s flow through a turbine to generate electricity. Unlike large-scale hydroelectric generation stations, which require significant infrastructure such as reservoirs and dams, small-scale hydroelectric projects can often be integrated into existing infrastructure, such as irrigation canals or fast flowing rivers.
The disadvantage of hydro is that there are few locations in New Zealand at large scale. For run-of-the-river hydro, it will only generate electricity when there is sufficient water flow, and even then, generation varies with water flow. There may also be difficulties in obtaining land, resource consents, and connecting to the grid.
5.4 Battery Energy Storage
Energy storage systems, including battery energy storage systems, can be used to store electricity during times of low demand or low cost and then discharge it during periods of high demand, high cost, or emergencies. This is one of the “saviours” of intermittent generation. Batteries can help to balance the grid, improve reliability, and reduce the need for expensive peaking generation stations. Batteries can also assist with voltage regulation on the grid, as well as providing fast acting ancillary services.
Battery energy storage systems can be charged from renewable sources such as solar or wind power, making them a clean and sustainable solution for grid energy storage. Additionally, they can be located at various points throughout the grid or within customer installations, providing localised demand control, backup power or reducing the need for costly transmission and distribution infrastructure upgrades.
Overall, integrating energy storage into the grid can help to increase the efficiency and resilience of the electricity system while also supporting the integration of renewable energy sources.
5.5 Demand Response (DR)
Remotely controlling electrical equipment within homes and business premises can be a powerful tool for managing energy demand and avoiding blackouts both within premises as well as on the grid. This approach is known as demand response and involves reducing or shifting electricity usage during peak periods when demand is high, and the grid is under stress.
By reducing demand during critical times, demand response can help balance supply and demand, maintain grid stability, and avoid the need for rolling blackouts or other grid emergency measures.
By incentivising energy users to reduce their demand during peak periods, grid operators can avoid or delay the need for new electricity generation stations, transmission, and distribution lines, reduce greenhouse gas emissions, and improve the reliability and resilience of the grid.
DR programs can range from simple price signals that encourage consumers to reduce energy usage during peak periods, to more sophisticated systems that allow larger premises or networks to remotely control appliances and other equipment to reduce demand. These programs can be voluntary or mandatory, and they can be targeted to specific customer groups, such as residential, commercial, or industrial users. A good example of DR is New Zealand’s ripple controlled hot water control system that has reliably reduced grid and electricity generation demand since the 1950s.
In addition, implementing Demand Response solutions can provide the following advantages for grid operators or end users:
- A valuable tool for grid operators and networks to manage demand on the grid, deferring costly investment.
- A valuable tool for network operators to utilise when remeshing their networks to enable supply before, during or after a disaster (or network maintenance), enabling critical electricity usage to remain connected.
- Participating in a DR program can help customers save money on their electricity bills, as they can take advantage of lower delivered electricity prices during off-peak periods. DR can also help consumers avoid or delay the need for expensive upgrades to their electrical installation, as they can reduce their energy usage during peak periods without having to invest in additional capacity.
6 How Shape Can Deliver DER Solutions
Shape Energy are able to provide a range of distributed energy resource systems at scales suitable for both gird operators, networks, and end users, with control systems to regulate and make best use of the renewable electricity available as well as minimising the delivered cost of electricity.
6.1 Microgrid Solutions
Microgrid solutions are suitable for implementation both for businesses and network providers. What our solution looks like depends on who it is being implemented for:
- For business premises, we are able to provide a grouping of distributed energy resources working with your interconnected loads, acting either as a single controllable group or a local microgrid solution. Microgrids provide the opportunity to utilise the lowest cost source of electricity within your premises, reduce or control your peak demand, provide emergency supply of electricity, and even the ability to arbitrage wholesale market and delivered electricity costs.
- For networks, we are able to provide batteries and diesel engines as emergency standby, peak control, or voltage support. Microgrids provide the opportunity to create semi self-sufficient sections of a network that can still financially clear in the wholesale electricity market but defer expenditure on network infrastructure. We are also able to integrate with existing batteries, diesel engines and plant.
Our engineers can assess your sites to identify the feasibility of a microgrid based on your load and generation needs, providing a detailed design that is customised for you. The microgrid can contain a combination of the distributed energy resources, including solar, battery, wind, hydro, or emergency diesel standby generation. We have an extensive internal supply chain and installation staff, as well as our partnerships in the industry.
Microgrids are complex systems that incorporate a large number of constituent elements, both in the form of your existing electrical devices, uses, and connections, your future planned upgrades and changes to those systems, as the new elements that we will introduce in providing the microgrid. These elements and the way they interact need to be understood in order to determine a solution that meets your individual energy and sustainability needs. That is why we begin our microgrid projects with creating a full system model of a microgrid design.
Once we have sign-off on the detailed design for the microgrid, we begin physical works. While the installation of some distributed energy resource systems will need to be done on site, namely any identified solar, HV reticulation, wind, battery, hydro installations, or diesel engines, we are able to perform significant manufacturing works off-site to mitigate the impact of construction works disrupting site operations. This may include pre-packaging components such as energy storage, standby generators, and switchboards into modular relocatable containers. The use of a modular system considerably speeds up the installation and connection process, as well as simplifying the relocation process if the site is reconfigured in the future.
The completed project will result in an advanced microgrid solution that could also enable your new local electricity generation assets to keep your premises or local grid running even when issues occur with the larger New Zealand grid depending on the design options selected. It will also enable resilience and reliability of supply for sites in remote areas where there is no grid connection. Shape Energy’s microgrid solutions allow local energy assets to integrate to minimise energy costs and maximise renewable electricity use.
6.2 Powerblok Containerised Energy Storage
The major element of a microgrid systems that employs a range of distributed energy resources is the local battery energy storage system. It allows other resources connected locally to generate even when demand is low, storing the extra electricity for later use. For this reason, we have made this distributed energy resource a particular focus of our work in the microgrid and DER areas. We have designed and built a turnkey containerised battery energy storage system that allows grid-scale power management to easily be deployed onto premises or sections. We call this solution Powerblok. It is suitable for peak-load shifting, co-incident demand management, dynamic capacity increase, voltage stability peak and frequency regulation as an ancillary service, off-grid standby power and other innovative applications.
Powerblok has been developed using the experience and knowledge we have gained installing and maintaining critical backup power systems for more than 20 years. Over that time, we have learned that site works bring additional risk, time, and cost.
Our solution is to deploy a premanufactured and designed solution. Powerblok comes housed in a 10, 20, or 40ft standard container that can easily be transported to site ready for installation. It can also easily be relocated if the need arises. Whether the Powerblok will be relocated in future, or housed on a site permanently, a containerised battery solution is a cost-effective way of housing batteries and switchgear while maximizing quality, safety, efficiency, and maintainability.
Powerblok is suitable for a wide range of applications, including business as usual, disaster recovery, construction environments, and even more direct interaction with the wider power grid. Powerblok is well suited to provide a cost-effective, and secure environment for production hardware, while also being a viable option for project-based environment requirements as it can be deployed more efficiently than traditional on-site generation. It can easily be established as a permanent or a portable energy supply in a disaster recovery environment, giving easy access to flexible, stored emergency power as it could also be delivered fully charged.
6.3 Demand Response via IoT Asset Monitoring
In situations where the resiliency of your electricity supply is a top priority, full visibility of your systems assists in responding to stress being put on your systems. Understanding what systems you have, the amount of load they draw, and how long they are able to run for when your grid connection is down or constrained, and you have to rely on local resources. It will let you respond to issues before they arise. In standard settings, this may allow you to react to events, and keep your operations running where they might otherwise fail when there is an electricity outage through sufficient installed DER and DR capacity. In emergency situations this also give you the ability to keep critical systems online for your local community.
Thanks to our relationship with Shape Technology, another division of Shape Group, we are able to give you visibility over your energy resources and your loads with IoT remote monitors and sensors. We are able to give you a full understanding of your premises or network by connecting your assets to our cloud-based asset management platform, OPLEX. OPLEX gives you the data insights you need to make energy consumption decisions and ensure that your grid or premises is ready for any situation.
With onboard controllers and Shape Technology Edge Gateway Devices deployed to your equipment, you will also be able to control those devices remotely as needed. This allows the platform to turn off non-vital equipment to reduce your power demand, as necessary. This can allow your more vital operations to continue through periods of stress on your grid connection or local energy resources.
Distributed energy resources can play a significant role in preparing for a future with increasing electrical demand and further threats to the electricity grid. By using renewable energy sources and energy storage, you can increase the resilience and reliability of your energy infrastructure. This is especially important in New Zealand, where dry years and large-scale events can put significant stress on the system.
Shape Energy is committed to providing distributed energy resources to New Zealand businesses and the electricity grid. By connecting small to medium scale power generation, storage, and control equipment, a decentralised network of power systems can be created that can help to balance supply and demand in real-time, without the risk of failure inherent in the current centralised system. We are ready to design, supply, install, and maintain these distributed energy resources as New Zealand starts down the road of implementing this important infrastructure.
Abele, E., Panten, N., & Menz, B. (2015). Data Collection for Energy Monitoring Purposes and Energy Control of Production Machines. Procedia CIRP, Volume 29, 299-304.
Albadi, M., & El-Saadany, E. (2007). Demand Response in Electricity Markets: An Overview. IEEE Power Engineering Society General Meeting, (pp. 1-5). Tampa.
Australian Energy Market Commission. (2018, April 1). Distributed Energy Resources. Retrieved from AEMC: https://www.aemc.gov.au/energy-system/electricity/electricity-system/distributed-energy-resources#:~:text=Distributed%20energy%20resources%20(DER)%20refers,battery%20storage
Electricity Authority. (2015, January). Interconnection asset capability. Retrieved from Electricity Authority: https://www.ea.govt.nz/operations/transmission/grid-management/interconnection-asset-capability/
Electricity Authority. (2022, November 10). Hydro lakes, dry summer risk and spot electricity prices. Retrieved from Electricity Authority: https://www.ea.govt.nz/about-us/media-and-publications/market-commentary/market-insights/hydro-lakes-dry-summer-risk-and-spot-electricity-prices/
Hannan, M., Wali, S., Ker, P., Abd Rahman, M., Mansor, M., Ramachandaramurthy, V., . . . Dong, Z. (2021). Battery energy-storage system: A review of technologies, optimization objectives, constraints, approaches, and outstanding issues. Journal of Energy Storage.
International Energy Agency. (2022). Unlocking the Potential of Distributed Energy Resources. IEA.
Jakhrani, A., Othman, A., Rigit, A., Samo, S., & Kamboh, S. (2012). Estimation of Carbon Footprints from Diesel Generator Emissions. International Conference on Green and Ubiquitous Technology (GUT).
Ministry of Business, Innovation, and Employment. (2019). Electricity demand and generation scenarios: Scenario and results summary.
Ministry of Business, Innovation, and Employment. (2021). Investigation into electricity supply interruptions of 9 August 2021. MBIE.
National Institute of Water and Atmospheric Research. (2018, February 12). Hydro. Retrieved from NIWA: https://niwa.co.nz/our-science/freshwater/tools/kaitiaki_tools/land-use/energy/hydro
Sagan, S. D. (2004). Learning from Normal Accidents. Organization & Environment, 2-4.
Transpower. (2022, October 20). ACOT – proposed TPM-related amendments. Retrieved from Transpower: https://tpow-corp-production.s3.ap-southeast-2.amazonaws.com/public/uncontrolled_docs/TP_Sub_ACOT_TPM_code_amendments_20Oct2022.pdf?VersionId=h_bp_jNEcULqiKYEQXopSVhWqtajKg88
Transpower. (2022, October 23). Distributed Energy Resources. Retrieved from Transpower: https://www.transpower.co.nz/our-work/distributed-energy-resources
Transpower. (2023). Interconnection asset capacity and grid configuration Annual Report 2021-2022. Transpower.
Transpower. (2023, February 14). Transpower declares Grid Emergency. Retrieved from Transpower: https://www.transpower.co.nz/news/transpower-declares-grid-emergency
United States of America National Electrical Manufacturers Association. (2021, October 10). Backup Power Systems. Retrieved from NEMA: https://www.nema.org/storm-disaster-recovery/backup-generation/backup-power-systems
United States of America National Renewable Energy Laboratory. (2017, May 5). Microgrids. Retrieved from NREL: https://www.nrel.gov/grid/microgrids.html
University of Canterbury. (2022, September 29). Developing a resilent electrical grid for New Zealand. Retrieved from University of Canterbury: https://www.canterbury.ac.nz/news/2022/developing-a-resilient-electrical-grid-for-new-zealand.html
Venuto, D. (2022, June 28). Key reasons NZ will keep getting power blackouts. Retrieved from NZHerald: https://www.nzherald.co.nz/nz/the-front-page-key-reasons-nz-will-keep-getting-power-blackouts/7CVJTQIGD4O5T2XZNNGOZZRGGQ/