"Four ways rooftop solar and household batteries can help the grid", Sophie Vorrath, Renew Economy
1. Avoided/deferred augmentation
“Increased DER capacity may lead to avoided/deferred transmission augmentation as it may reduce the amount of load supplied from within distribution networks and reduce peak demand at transmission connection points. It may also lead to avoided/deferred distribution augmentation, as it increases the amount of load supplied from within distribution networks and may reduce peak demand at upstream network assets.”
2. Avoided replacement/asset derating
“Increased DER capacity can lower the average load on network assets, enabling asset deratings and when replacement is required, smaller, cheaper assets can be installed,” the draft says.
“DNSPs may quantify these benefits where the proposed investment to increase hosting capacity leads to changes in other parts of the network where: peak demand is not growing over time at the relevant network asset; peak demand coincides with times when DER exports are enabled; network asset longevity can be improved by reducing loads.”
3. Reduced line losses
“Increases in DER generation may result in avoided transmission and distribution losses. DER generation can supply loads within the distribution network, reducing the supply from centralised generators connected to distribution networks by transmission lines, which avoids energy being lost to heat when transported over transmission lines. It can also reduce the distance the energy travels across the distribution network compared to centralised generators, which reduces the amount of energy lost to heat when transported over distribution lines.”
4. Improved reliability
“DER can supply individual customers and/or local networks after network faults, where it can be islanded, reducing unserved energy and outage duration,” the draft says, adding that this is only quantifiable if theDER in question enables an increase in flexible energy generation and/or flexible capacity, and where batteries are included, such as in VPPs and microgrids.
“Specifically, this value stream may be quantified where: The proposed investment includes or incentivises additional investment in battery storage (which would otherwise not be installed); the additional battery investment is able to be islanded during a fault; outages of up to a few hours are common.”
*Environmental benefits
According to the AER, this is about the benefits of avoided greenhouse gas emissions due to additional DER. Of course, “these can only be quantified if there is an identifiable tax, levy or other payment associated with environmental or health costs which producers are required to pay or where jurisdictional legislation directs DNSPs to consider the impact of these externalities and has provided a value that is to be used.”
The guidance note goes on to say that “renewable energy targets and/or a potential carbon price for generators should be incorporated into the DNSP’s calculation of wholesale market benefits. If there is a jurisdictional requirement to consider the price of carbon, the DNSP should calculate the carbon benefits associated with its proposed investment.”
**Intangible benefits
According to the AER, these might include such consumer benefits as “a sense of empowerment, autonomy and resilience,” which could serve as motivation for consumers “to pay a premium to invest in DER or accept reduced revenue from their DER investment.”
While the Regulator acknowledges that some customers may value these intangible (or non–monetary) benefits, it says DNSPs should not include them in their investment calculations. “In line with the RIT–D principles, credible options should maximise the present value of the net economic benefit to all those who produce, consume and transport electricity in the NEM,” it says.
https://reneweconomy.com.au/four-ways-rooftop-solar-and-household-batteries-can-help-the-grid/