10 Ways to Prepare Your Grid for Solar Interconnection
Electric Light & Power. February 28th, 2012
By Hisham Othman, Ph.D., Petra Solar
Nationwide, more and more utilities face policy mandates to adopt renewable generation. While integrating renewables such as solar power delivers clear payoffs, it requires utility professionals to successfully navigate regulatory hurdles, community relations, power quality control and distribution management. Here are the ten most critical steps utilities must undergo when integrating renewables.
1 Examine the economics.
The economics of solar vary by location. Factors such as fuel cost, the availability of state incentives and insolation (the amount of sun that falls on a region throughout a year) all influence the bottom line. Even regions with current access to affordable fossil fuels cannot count on the predictability of future prices. Factoring in "externalities" (economic costs traditionally excluded from bottom-line calculations) such as pollution and carbon emissions makes solar a clear economic winner.
2 Get the regulatory case in order.
It's important to begin the conversation with regulators early in the deployment process. For example, local regulations might specify whether a distribution company can own its own generation assets, whether there are feed-in tariffs in place to incentivize solar and whether the solar investment can be added to the regulated asset base. Establishing your regulatory case is critical to determining return on investment. (In other words, it is necessary information for fully completing Step 1.)
3 Choose between utility- and consumer-owned solar.
One of the most significant choices utilities face is whether to purchase solar assets or to encourage property owners to purchase them. Utility-owned solar can prove to be a money-maker for the utility by putting in place a solid long-term generation asset, but it demands a more significant upfront investment. Ratepayer-purchased solar, on the other hand, requires less upfront investment from utilities and lessens demand on existing generation assets, but it means utilities forego revenue from selling electricity and often requires a significant ongoing maintenance effort.
4 Choose between centralized and distributed solar.
Large, utility-owned solar farms have their benefits; they are well defined within the transmission and distribution system and are relatively easy to manage. Nevertheless, distributed solar—local sources of solar energy on rooftops, utility poles and other existing infrastructure—has a number of advantages over centralized solar farms. Distributed solar is often easier to site and permit and has a lower negative impact on the environment than centralized solar. Distributed solar installations also hedge against the possibility of local weather events, such as passing clouds, impacting generation. Additionally, a happy outcome of deploying distributed solar is that the distribution includes building distributed sensors and meters across the network. This translates into building a smart grid as you go, a fact that adds significant value to a deployment and changes the economics of distributed solar considerably.
5 Decide how to finance your solar.
One finance option is a power purchase agreement (PPA), in which a developer builds the solar system and the utility signs a 20-year to 25-year agreement with them to purchase power. Another option is to lease equipment through a bank and sell the energy the equipment generates, or utilities may elect to invest directly and increase the asset base.
6 Design your communications infrastructure.
Distributed solar power offers a huge opportunity to deploy advanced grid communications without significant infrastructure adjustment. Distributed generation assets, such as solar panels placed on utility poles, can house communications devices to monitor grid activity and prevent blackouts.
7 Consider reactive power needs and capabilities.
Reactive power requirements to ensure voltage quality—in which reactive energy flows and there is no net transfer of energy to the load—may be changed by the integration of high levels of solar. Incremental reactive power requirements can be specified to be integrated within the solar panel inverter. Alternatively, the utility can build a reactive support on the circuit to address all the needs of the local community.
8 Examine system management.
Consider how to integrate solar assets within utility operations. Assuming a utility has decided on distributed solar with some communications and monitoring capabilities, the utility will start collecting a massive amount of data including voltages, frequencies and temperatures. Make good use of this valuable data and use it to drive operational improvements. Integrate all of the incoming data into the distribution management system (DMS), SCADA, graphical information system (GIS) and outage management system (OMS).
9 Get the community involved.
Ensure that the community knows in advance and fully understands its new assets. Address community members' concerns from the outset with a dual goal of stemming criticism and of drumming up enthusiasm. Community enthusiasm for solar will ease your deployment process and allow you to roll out demand response programs in the future. This step is simple when people are educated on the potential financial benefits from solar.
10 Think long-term. Take advantage of your new assets to integrate emerging technologies and meet challenges as they develop. Planning for distributed solar also prepares the grid for future developments like electric vehicle charging stations and energy storage. Like a human, a smart grid has ears to listen, a voice to communicate, a brain to process information and the capability to mature over time. Capitalize investments in solar to cultivate that grid, enabling it continually to grow smarter.
Hisham Othman, PhD, is vice-president of professional services and manager MEA at Petra Solar; he leads corporate consulting services globally and manages corporate activities in the Middle East and Africa.