Portugal just ran its entire grid for 107 straight hours on 100% renewables. That’s four and a half days. The country now gets about 48% of its energy from green power.
Tag Archives: solar power
A brief reply to “Real” Electricity Still Comes from the Grid
Source: “Real” Electricity Still Comes from the Grid
Catherine Wolfram at UC Berkeley posted about their paper looking at costs of distributed energy systems in Kenya and concluding that these were too expensive for households compared to connecting to the grid. However, the paper came under immediate criticism.
Here’s my thoughts based on her representation of the paper’s findings, some of which are mirrored by other commentators:
First, the paper talks about costs on one side, but doesn’t put them in perspective to the alternatives. The post lists the cost of the individual systems, but not the expected connection costs to the grid.
Further the paper takes a static look at current costs and doesn’t account for the differential trends in the sets of costs for an home-based system versus connecting to the grid. The latter costs can be expected to be steady or even rising, while it’s well known that both solar and storage costs have fallen rapidly.
Different scales of “grid” also are important. For example, solar projects show scale economies up to about 3 MW but then modular construction flattens the per kW cost. A village microgrid separate from a national central grid may be quite cost competitive.
Finally, the paper appears to lump large hydro in with other utility-scale renewables. The environmental (and economic development) record for large-scale hydro projects in the developing world is dubious at best. There is evidence of significant methane emissions from tropical reservoirs. Habitat is destroyed and poorly designed projects don’t deliver expected benefits. Hydro is by far the largest energy supplier on these grids, and they may be little better than coal from an overall environmental perspective.
Reblog: If you like your time-invariant electricity price, you can keep it
Severin Borenstein at the Energy Institute at Haas makes the case for giving customers the choice of TOU or fixed price rates. I’ve commented several times on the Energy Institute blog about this approach, and blogged myself about the need for this option.
Source: If you like your time-invariant electricity price, you can keep it
Do we really need more storage for our renewables?
PG&E has been running a series of “advertorials” on clean energy in the Sacramento Bee and other papers. Today’s on the need for electricity storage caught my eye. I’m not sure that we need new storage in California, at least not large-scale, in the immediate future.
The PG&E article describes an event in February 2014 when California generated more energy, much of it from solar and wind, than consumers were using. PG&E raises this as a concern that should be addressed so as not to lose that energy. But PG&E’s premise ignores one critical point–California is not isolated–it’s connected to many other states.
California is the largest electricity consumer in the Western Interconnection (with 10 other states and parts of Canada and Mexico). However the state only represents 30% of Western load. All of those states have weaker directives on renewables and greenhouse gas emissions, and most have much larger portions coming from high-emitting coal-fired plants.
When California overgenerates from renewables, it exports that power to those other states. This leads to a reduction in natural gas and coal use. When California needs power, it imports power as it has been doing for decades. In other words, the rest of the Western Interconnect is already acting like a storage device. The Southwest utilities have long exported excess coal-fired power overnight to California at low prices. Now California can turn the tables. PG&E may not be getting renewable portfolio standard (RPS) or greenhouse gas reduction credits for those exports, but they reduce GHG emissions in other states.
This situation is similar to the recent rise in petroleum production in the U.S. The country now exports refined products thanks to advances in extraction technologies. Congress is considering whether to allow the export of crude oil. For both California and the U.S., the concept of exporting energy has been inconceivable up to now. Time to rethink our paradigms?
How Should Distributed Generation be Distributed?
Bruce Mountain observes in the Comments that Australia already is experiencing deep solar penetration, but is not find extensive disruptions in the distribution networks.
Smart, clean and local energy technologies for Davis
Second in a series published in the Davis Enterprise on how the City of Davis can address its energy future:
Three key steps in designing rates for solar power
KQED posted a good summary of how solar power is driving the residential rate design rulemaking at the CPUC. (M.Cubed works for EDF there.) I offer three steps that should be taken to address the issues of how to change ratemaking for a changing energy marketplace:
1) Consumers should see time varying prices (time of use or TOU being among that menu). Tiered rates make it impossible to see the current price for consumption, and tiered rates have been shown not to induce any additional conservation across the customer base. Consumer surveys show that customers want more control over their electricity use and the price signals to direct them.
2) Consumers should be offered a meaningful menu of rate options. This means rates that differ in risk exposure both over time of day and time horizon. Customers should be able to hedge against peak day prices or participate in demand response. They should be able to accept changes in hourly prices or buy a multi-year contract. Utilities already offer these contract options to their suppliers; why not treat their customers as they they are valued?
3) Any calculation of grid costs and responsibility should reflect the changing demand by consumers. The grid charges proposed by the utilities assume that future consumers will install the same-sized equipment as they do today and that they will consume in the same pattern. Solar panels are ready today to “island” a home from the network, and EV charging could create greater load diversity even at the circuit level. That will radically change utility investment. The distribution planning rulemaking is an important step toward resolving that issue but the CPUC hasn’t yet linked the proceedings.
Only the first issue is being addressed head on in the rulemaking and it hasn’t really delved into the importance of emerging consumer choice.
Making Community Solar Gardens Work
California has been quite successful at encouraging the development of (1) large utility-scale renewables through the renewables portfolio standard (RPS) and other measures and (2) small-scale, single structure solar generation through the California Solar Initiative (CSI) and measures such as net energy metering (NEM). However, there have been numerous market and regulatory barriers to developing and deploying the “in-between” community-scale and neighborhood-scale renewables that hold substantial promise.
Community-scale and neighborhood-scale distributed generation (DG) includes some technologies that simply are not cost-effective at the small scale of a single house or business, but are not large enough to justify the transaction costs of participating in the larger wholesale electricity market. These resources, such as “community solar gardens”, can meet the demands of many customers who cannot take advantage of adding renewables at their location and can also reduce investment in expensive new transmission projects. Examples of these types of projects are parking structure-scale solar photovoltaics, solar-thermal generation and space cooling, and biogas and biomass projects, some of which could provide district heating. Technology costs are falling so rapidly that these mid-scale projects are becoming competitive with utility-scale resources when transmission cost savings are factored in. SB 43 (Wolk 2013) recognizes that the promise of mid-scale renewables has not been realized.
In response to SB 43, each of the large investor-owned utilities–PG&E, SCE and SDG&E–have filed proposed tariffs with names such as Enhanced Community Renewables Program or Share the Sun. I filed testimony in the PG&E and SCE cases on behalf of the Sierra Club addressing shortcomings in those programs that would inhibit development of community solar gardens. SDG&E’s proposal, while not perfect, better meets the law’s objectives. After the hearings, the CPUC postponed a proposed decision from the July 1 deadline to October.
SB 43’s requirement that the investor-owned utilities “provide support for enhanced community renewables programs” is a critical step forward for California’s distributed energy goals. The CSI is the state’s premier distributed generation program. In SB 43 the Legislature expressed its intent that the “green tariff shared renewables program seeks to build on the success of the California Solar Initiative by expanding access to all eligible renewable energy resources to all ratepayers who are currently unable to access the benefits of onsite generation.” SB 43 advances the success of the CSI into the area of multifamily residential and multitenant commercial properties and introduces all types of renewable energy resources. Customers who, for various reasons, cannot benefit from the current net metering programs, will be able to benefit through SB 43.
The Legislature clearly intends for this program to lead to a transformation in the energy market akin to the success for single customers of the CSI. This necessary market transformation extends to multifamily and commercial lease properties that are currently beyond the CSI and Self Generation Incentive Programs (SGIP). The Commission should ensure that utilities’ programs under SB 43 provides the market transformation that is necessary for this underserved segment.
State regulations calls for all new residential dwellings to consume zero-net energy (ZNE) by 2020, and all new commercial properties by 2030. Fully implementing the market transformation identified in SB 43 is one of the obvious means to achieve this target. The CSI option has already facilitated many examples of feasible ZNE single-family homes using renewables well ahead of the 2020 deadline. There are several market barriers to integrating renewables in a similar manner on multifamily and commercial leased properties and on single-family that are not favorably located or that have other impediments.
A properly-designed community solar garden program should provide a critical work-around for the split-incentive problem that has plagued local renewable development in California. The split-incentive problem arises from the fact that multi-tenant structures, both commercial and residential, may not be able to implement solar or other renewable resources due to the fact that lessees are not the owners of the shared space where renewables could be sited. The problem of split-incentives between landlords and tenants has long been recognized, and has been the focus of energy efficiency programs.
As a corollary, the Commission should provide individual developers and property owners the opportunity to integrate energy efficiency and DG measures to achieve the best mix for meeting environmental and economic goals. Each project is unique so that a “one size fits all” approach that requires sale of all output into the wholesale market with buyback from customers who may have no connection with the project will only discourage enhanced development.
For distributed generation to expand in California there must be a cost-effective path for residential and commercial tenants, as well as not-well-situated buildings, to install solar and other renewables and share the costs among other customers. The focus to date has been on either utility-scale or single-building scale projects, but the most promise may be in mid-scale projects that can serve a community or a neighborhood cost-effectively through a combination of scale economies and avoided transmission and distribution investment. But to achieve this objective requires changes from current utility practices.
An update: Here’s the link to the decision on this CPUC case issued in January. And here’s the link to scoping memo for the phase of this proceeding.