Climate Change

By: Clear Energy Alliance

It appears that the White House and at least two of the Executive Branch Agencies are not on the same page of the climate change “playbook”. The Administration has clearly enunciated goals of eliminating coal use by 2030, achieving fossil-free electric generation by 2035 and achieving Net Zero CO2 emissions by 2050.

The US Energy Information Administration (EIA) Annual Energy Outlook 2022 projects that petroleum and natural gas will remain the most-used fuels in the United States through 2050, based on consumer preferences, as shown in the graph below.

This projection is inconsistent with the Administration’s Net Zero goal. EIA projects total energy consumption of approximately 108 Quads, of which approximately 75 Quads is petroleum, other liquids and natural gas in 2050. Other renewable energy (predominantly wind and solar) increases from approximately 3 Quads to approximately 18 Quads, far short of the intended transition to a renewable plus storage goal with limited nuclear, hydro and liquid biofuels. Coal decreases from approximately 10 Quads currently to approximately 8 Quads by 2030 and to 6 Quads by 2050, rather than to zero by 2030 as proclaimed by climate czar John Kerry.

Similarly, the US National Renewable Energy Laboratory (NREL)projects that even what is described as “widespread electrification”, the high growth scenario projects electric consumption growth of 67%, mostly in increased consumption in the transportation sector (EVs). Note that this study is now 4 years old and was conducted during the previous Administration, prior to the goals set by the current Administration. The projected growth of electric consumption is far short of that which would result from the implementation of an “all-electric everything” goal to be achieved by 2050.

In its June 2018 Electrification Futures Study, the National Renewable Energy Laboratory (NREL) projects that even with “limited impacts” from electrification, U.S. electricity consumption could increase 21% over the 2016–2050 period (using moderate assumptions about technology changes), resulting in a compound growth rate of 0.65% per year. In the medium and high scenarios, which assume “widespread electrification,” electric consumption growth is 45% and 67%, respectively (compound annual growth rates of 1.2% and 1.6%, respectively). Source: NREL

This is not to suggest that these projections could not be changed if consumer preference is superseded by government fiat, as now appears likely to occur. However, replacement of three-quarters of projected future energy consumption with renewables plus storage would be a massive and extremely expensive undertaking. It would include abandonment in place of more than $50 trillion of fossil fuels, abandonment of large numbers of coal and natural gas generators before the ends of their useful lives and the installation of more than 1,000 GW of new wind and solar generating capacity (actual, not nameplate) plus storage capacity sufficient to carry the grid through the longest anticipated wind or solar “drought”. The storage technology required by this transition is not currently available.

By: Cleaning up with Michael Liebreich

The fossil-free, all-electric everything grid envisioned to avoid catastrophic anthropogenic climate change would be a very different grid from that which serves the US today. The fossil-free grid would still include the non-fossil generation currently in service, including hydroelectric, geothermal and biomass generators; and, possibly, some existing and even new nuclear generation.

The all-electric everything transition would require a grid with approximately four times the capacity of the current grid, upgrading existing transmission and distribution infrastructure to handle the increased demand. The existing transmission infrastructure would also have to be expanded to connect a far larger number of smaller generators, frequently in remote locations at some distance from the existing infrastructure. The transmission infrastructure might also need to be restructured to permit longer distance transmission than is currently common.

The intermittent generators connected to the grid would either be required to be configured to be dispatchable with the addition of storage, or the grid would have to be equipped with sufficient storage at multiple locations to compensate for the intermittency or unavailability of multiple intermittent generation sites.

Configuration of each intermittent generation site to be dispatchable would require installation of equipment to increase the DC voltage output of the generators to the battery storage voltage, batteries to store surplus power, inverters to convert the DC to AC and transformers to increase the AC voltage to transmission voltage. The output of each dispatchable generator site would then be connected to the grid.

Configuration of each intermittent generation site to be non-dispatchable would require installation of equipment to invert the DC output of the generators to AC and transformers to increase the AC voltage to transmission voltage. The output of each non-dispatchable generator would then be connected to the grid.

Numerous locations on the grid would be required to install battery farms or other storage approaches to store power supplied by the intermittent generators in excess of grid demand. These battery farms would require the installation of rectifiers to convert the excess AC power from the grid to DC power at battery storage voltage as well as inverters to convert DC power drawn from the batteries to AC for redelivery to the grid at grid voltage when the current intermittent generator output was insufficient to satisfy the contemporaneous demand of the grid. The long-duration storage required for this grid is not currently commercially available. Other storage approaches, such as pumped hydro or compressed air storage, might use the AC power from the grid directly, but face difficult project approval processes.

The selection of the location for storage in the system has efficiency consequences. Assuming that each inversion and rectification step has an efficiency of 95% and that the batteries have a round-trip efficiency of 90%, the dispatchable generation configuration experiences losses of approximately 19% of the generated electricity, while the intermittent generation with grid storage configuration experiences losses of approximately 27% of the generated electricity.

The selection of the location for storage likely also has system investment consequences. The connection of multiple, independent intermittent generation sites to a common storage location might reduce the storage capacity required per unit of generation capacity because of the diversity of locations and generator types.

The type of intermittent generators would be expected to vary as a function of geography and wind and weather conditions. The northern tier of the US experiences lower solar insolation than the southern states, particularly in winter. The northern tier states also experience more snow and ice in winter, which would coat the solar collectors and reduce collection efficiency, periodically to zero. Wind installation in the northern tier states would experience periodic icing and might require the installation of wind turbines with heated blades to prevent or minimize icing, adding cost and parasitic power consumption. The southwestern US has far greater solar availability, but it is frequently located remotely from the loads it would serve. Offshore wind will likely be a significant factor near the coasts.

The current US electric grid has transmission and distribution losses of approximately 6%, of which transmission losses are approximately 1%. Designing the restructured electric grid to permit longer transmission distances would likely increase these transmission losses.

The design of a primarily intermittent renewable generation plus storage powered grid is a very complex problem. A satisfactory system design has yet to be demonstrated.

Energy independence has been an aspirational goal of the US for decades. However, the US actually achieved that goal in the period from 2017-2020 as the result of the application of US ingenuity and the encouragement of a supportive federal government. Energy was readily available at reasonable cost and the economy experienced robust growth.

Regrettably, a change in the federal Administration has ended both the recent energy independence and the robust economic growth. The US has now rejoined the Paris Accords and the Administration has committed to the destruction of the US fossil fuel industry and the restructuring of the US electricity sector and the entire US energy economy in an attempt to achieve net-zero CO2 emissions by 2050. Rapidly increasing energy costs and looming energy shortages are the result.

The Administration has halted oil and gas lease sales, slow-walked the issuance of drilling permits in existing oil and gas leases, slow-walked approvals for increases in oil refinery capacity, actively discouraged investment in new oil and gas projects and claims it can’t understand why oil prices have increased and oil supplies are declining. The Administration has been quick to blame rising prices and energy supply problems on the industry. Elements of the industry have adopted a posture of “orderly liquidation” of their businesses in the face of forced liquidation by government fiat.

Meanwhile, the Administration is incentivizing investments in wind and solar electric generation and subsidizing the purchase of electric vehicles and the construction of EV charging station infrastructure. Goals have been set for the end of coal-fired electric generation, the end of all fossil fuel electric generation, and the termination of the sale of vehicles with internal combustion engines. These federal goals are both market and technology forcing. They rely on the timely installation and operation of technologies which have not been invented or introduced into the commercial market.

Fabrication of wind and solar generation equipment, electricity storage and electric vehicles require large quantities of rare earth minerals, largely available from China and other non-friendly countries. These requirements render the US energy economy dependent upon unfriendly foreign governments for the maintenance and expansion of US energy infrastructure. Recent Russian actions to reduce energy deliveries to European nations provide a warning regarding potential future Chinese actions regarding the supply of rare earth minerals for wind, solar, storage, and EV applications.

Should the US allow itself to become totally dependent on wind, solar and storage for its electricity needs, it would be at great strategic risk when it came time to replace the first tranche of this equipment in approximately 20 years. The same would be true for dependence on EVs for our transportation system.

Perhaps the greatest risk, in the short term, is that the current energy and electric generation infrastructure will be driven from or retired from the market before the necessary replacement infrastructure is in place and operational. The current haphazard approach to infrastructure replacement has resulted in several failed demonstrations of a renewable intense generation infrastructure which would be disastrous if repeated at national scale.

Wind and solar are intermittent resources, so both wind and solar generation are intermittent and require backup. This backup is currently provided by conventional generation. However, with the evolution of a fossil-free grid, storage capacity would be required to provide backup. Additional wind and solar generating capacity would also be required to recharge storage when wind and solar again become available.

Storage must be capable of functioning under several different conditions. Some storage is currently being used with both wind and solar installations to smooth the output of the generators when the wind is fluctuating or when the sun is partially obscured by clouds. This storage has relatively limited capacity and responds quickly to fluctuations.

Storage is now beginning to be installed with solar arrays to deal with the typical increase in demand and consumption at the end of the day, when solar output has decreased or ceased. This “four-hour storage” has approximately half the capacity of the solar array during a normal day. This storage must be recharged the next day during periods when grid demand is less than solar array capacity, or must be recharged overnight or during the next day from other generation sources. This storage has a current cost of approximately $350 per kWh and is projected to decline in cost to between $150 and $100 per kWh by 2050 according to the National Renewable Energy Laboratory (NREL).

As the transition to a fossil-free grid progresses, there will be a growing need for long-duration storage capable of storing the output of wind and solar generators in sufficient quantities to power the grid for multiple hours to multiple days when either wind or solar, or both, are unavailable or significantly diminished. The “wind drought” which affected the United Kingdom and parts of Western Europe in the fall of 2021 is an example of a situation requiring such long-term storage. In that event, storage capable of powering the grid for 10 days would have been required, had conventional generation not been available.

Another situation requiring long-term storage is those periods when wind and solar output are diminished seasonally. EIA reports that, in 2021, solar photovoltaic system output was below 25% of rating plate capacity in the period from October through February, while (onshore) wind capacity was below 35% in the period June through October and in January and February. The January through February period is of particular concern because both wind and solar capacity are diminished. Long-duration storage would be required to make up the generation deficit for a period of several months.

Clearly, additional wind and solar generating capacity would be required to charge long-duration storage to supplement both wind and solar generation through the Fall and Winter, as well as to support the grid through a “drought” period. This long-duration storage is not currently commercially available. Technology capable of approximately 150 hours is currently under development, but would be insufficient to support the grid through a 10-day “drought” or through a multi-month period of insufficient generation.

The cost of such long-duration storage is currently unknown, but the storage capacity required to support a fossil-free grid would be very large and very expensive. However, the cost of not having long-duration storage in sufficient quantities would be substantially greater.

The expected service life of current grid-scale batteries is approximately 10 years, compared to the expected 40 year service life of utility assets. This difference dramatically increases depreciation expense and system ownership costs.

From: Friends of Science Calgary

By: Ken Gregory, P.Eng.

Date: December 21, 2021

The Cost of Net Zero Electrification of the U.S.A.

Executive Summary

Many governments have made promises to reduce greenhouse gas emissions by replacing fossil fuels with solar and wind generated electricity and to electrify the economy. A report by Thomas Tanton estimates a capital cost of US$36.4 trillion for the U.S.A. economy to meet net zero emissions using wind and solar power. This study identifies several errors in the Tanton report and provides new capital cost estimates using 2019 and 2020 hourly electricity generation data rather than using annual average conditions as was done in the Tanton report. This study finds that the battery costs for replacing all current fossil fuel fired electricity with wind and solar generated electricity, using 2020 electricity data, is 109 times that estimated by the Tanton report. The total capital cost of electrification is herein estimated, using 2020 data, at US$433 trillion, or 20 times the U.S.A. 2019 gross domestic product. Overbuilding the solar plus wind capacity by 21% reduces overall costs by 18% by reducing battery storage costs. Allowing fossil fuels with carbon capture and storage to provide 50% of the electricity demand dramatically reduces the total costs from US$433 trillion to US$24 trillion, which is a reduction of 94.6%. Battery storage costs are highly dependent on the year’s weather and the seasonal shape of electricity demand.

Introduction

The U.S.A. government has set a target to reduce greenhouse gas emissions from fossil fuel use and cement manufacturing to net zero economy-wide by no later than 2050. Some believe we could achieved this by replacing most fossil fuel use with non-emitting energy sources and sequestering carbon dioxide (CO2) emissions from the remaining fossil fuel use by carbon capture and storage (CCS).

This article provides an estimate of capital costs to achieve net zero emissions in the U.S.A. based largely on an analysis by Thomas Tanton in his report “Cost of Electrification: A State-by-State Analysis and Results”. [1] Estimating the increased operating costs is beyond the scope of this study. (continue reading)

The Cost of Net Zero Electrification of the U.S.A.

Solar is intermittent. Therefore, solar generation is intermittent. Solar is unreliably available during the day and reliably unavailable at night. Solar conditions vary geographically and seasonally. Therefore, solar generation potential varies geographically and seasonally. Solar generation has been implemented initially in the best locations for solar generation potential. However, expansion of solar generation would require installations in less than ideal locations.

US Energy Information Administration reports a capacity factor of 25% for solar generation. Virtually all solar generation in the US and globally is redundant capacity, in that it cannot replace dispatchable conventional generation in a reliable grid, though it can displace the output of that conventional generation when solar generation operates.

Solar arrays are typically proposed and reported based on the rating plate capacity of the solar generators. However, since the solar collector capacity factors are in the 25% range, their annual potential output is typically a quarter of the annual potential output of a conventional generator of the same rating plate capacity.

Solar generation must be supplied with full capacity backup to replace the solar generator output when the sun is not shining. This backup capacity is currently provided by the conventional generation fleet. This is also true of most rooftop solar installations. Some rooftop solar installations include storage plus excess solar collector capacity to permit them to operate independent of the utility grid.

Solar generation capacity cannot be permitted to increase beyond the capacity of the conventional generation fleet if the grid is to remain reliable. This situation could result from an increase in solar generation capacity or from a decrease in conventional generation capacity, or both.

The full cost of solar generation includes the capital, operating and maintenance costs of the solar array plus the capital and operating costs of the conventional backup generation required when the solar generation is unavailable. The solar industry typically ignores the real cost of conventional backup, so that it can claim that solar generation is cheaper than conventional generation.

As conventional generation is retired, either because of age and condition or because of environmental regulation or Executive Order, its capacity must be replaced by storage capable of storing the rating plate output of the conventional generators for the maximum period of time solar generation might be unavailable, plus additional solar generating capacity sufficient to recharge the storage in the shortest period of time between solar interruptions. In this case, the full cost of solar generation includes the capital, operating and maintenance costs of the solar array plus the capital, operating and maintenance costs of the storage and the extra solar generation capacity required to recharge storage.

Clearly, solar generation is not cheaper than conventional generation when its full costs are considered. Solar generation increases total generation investment in the short term, since it is redundant capacity. It also increases grid investment in the longer term, since it requires both storage capacity to backup the solar generation and additional solar generation capacity to recharge storage. The undepreciated investment in conventional generation retired by environmental regulation or Executive Order also remains as a grid investment, further increasing the cost of the solar generation plus storage which replaced it.

The expected service life of solar PV collectors is 20-25 years. This compares with the 40-year depreciation period for utility generation assets. This shorter service life expectancy increases the cost of ownership of the solar array.

By: PragerU

Wind is intermittent. Therefore, wind generation is intermittent. Wind is unreliably available around the clock. Wind conditions vary geographically and seasonally. Therefore, wind generation potential varies geographically and seasonally. Wind generation has been implemented initially in the best locations for wind generation potential. However, expansion of wind generation would require installations in less than ideal locations.

US Energy Information Administration uses a capacity factor of 40% for new onshore wind generation. The International Energy Agency uses a capacity factor of 50% for offshore wind generation. Virtually all wind generation in the US and globally is redundant capacity, in that it cannot replace dispatchable conventional generation in a reliable grid, though it can displace the output of that conventional generation when wind generation operates.
 
Wind farms are typically proposed and reported based on the rating plate capacity of the wind generators. However, since the wind turbine capacity factors are in the 40-50% range, their annual potential output is typically half, or less, of the annual potential output of a conventional generator of the same rating plate capacity.

Wind generation must be supplied with full capacity backup to replace the wind generator output when the wind is not blowing, or is blowing at too high a velocity for the turbines to operate. This backup capacity is currently provided by the conventional generation fleet.

Wind generation capacity cannot be permitted to increase beyond the capacity of the conventional generation fleet if the grid is to remain reliable. This situation could result from an increase in wind generation or from a decrease in conventional generation capacity, or both.

The full cost of wind generation includes the capital, operating and maintenance costs of the wind farm plus the capital and operating costs of the conventional backup generation required when the wind generation is inoperable. The wind generation industry typically ignores the real cost of conventional backup, so that it can claim that wind generation is cheaper than conventional generation.

As conventional generation is retired, either because of age and condition or because of environmental regulation or Executive Order, its capacity must be replaced by storage capable of storing the rating plate output of the conventional generators for the maximum period of time wind generation might be unavailable, plus additional wind generating capacity sufficient to recharge the storage in the shortest period of time between wind interruptions. In this case, the full cost of wind generation includes the capital, operating and maintenance costs of the wind farm plus the capital, operating and maintenance costs of the storage and the extra wind generation capacity required to recharge storage.

Clearly, wind generation is not cheaper than conventional generation when its full costs are considered. Wind generation increases total generation investment in the short term, since it is redundant capacity. It also increases grid investment in the longer term, since it requires both storage capacity to backup the wind generation and additional wind generation capacity to recharge storage. The undepreciated investment in conventional generation retired by environmental regulation or Executive Order also remains as a grid investment, further increasing the cost of the wind generation plus storage which replaced it.

The expected life of wind turbines is 20-25 years. This compares to the 40-year depreciation period typical for conventional generation, increasing the annual ownership costs of the wind farm.

Dominion Energy has proposed Coastal Virginia Offshore Wind (CVOW), the first large offshore wind project in the United States. CVOW would be a 2.6 GW wind farm consisting of 176 15 MW wind turbines, 3 offshore electric substations, underwater and onshore power delivery cables, a collector station and an interconnection to the existing Dominion grid.

The estimated cost of the project is $10 billion, or approximately $57 million per wind turbine. The 15 MW Siemens Gamesa wind turbines are the largest commercially available wind turbines and will be mounted 800 feet above mean sea level, approximately 27 miles offshore of Hampton, VA.

The International Energy Agency (IEA) estimates the annual capacity factor of offshore wind turbines at 50%. I will use this estimate, since there is no commercial experience with these new wind turbines and no experience with offshore wind turbines in the Norfolk, VA area. At this capacity factor, the actual average annual capacity of the CVOW wind farm would be approximately 1.3 GW, fluctuating over a range from 0 – 2.6 GW. The output of the CVOW wind farm, as proposed, is non-dispatchable. Therefore, it would require either conventional generation backup or massive electricity storage capacity.

The daily average power generated by the CVOW wind farm would be approximately 31 GWh (1.3 * 24). Therefore, storage capacity of approximately 31 GWh would be required to replace wind farm output for each low/no wind day. Replacing wind farm output over a 10-day wind drought similar to that experienced in the UK and Western Europe in the Fall of 2021 would require long-duration storage of more than 300 GWh. Such long-duration storage is not currently commercially available and there is no schedule for its commercial availability.

The National Renewable Energy Laboratory (NREL) estimates the current cost of 4-hour battery storage at $350/kwh. This cost is projected to drop to an average of $150/kWh by 2050. Since long-duration storage capable of a 10-day operating cycle is not commercially available and its future cost is unknown, I will use the current cost of 4-hour storage to estimate the cost of making the output of the CVOW wind farm dispatchable. The approximate 300 GWh long-duration storage requirement is equal to 300,000,000 kWh, at a storage system cost of $350/kWh, or a total cost of approximately $105 billion, or approximately 10 times the cost of the wind farm.

Storage is a passive component of the overall wind energy system. Storage must be charged with surplus electricity generated by the wind farm or elsewhere in the Dominion grid; and, it must also be recharged after each use. While this could be accomplished today using the Dominion grid’s conventional generation capacity reserve margin, charging and recharging in a renewable plus storage grid would require additional renewable generating capacity beyond the capacity required to serve the contemporaneous demand of the grid. The additional renewable generating capacity required to charge and recharge storage would be determined by the number of days allowed for charging and especially recharging storage.

By: Cutting Through The Noise

“A goal without a plan is just a wish.”, Antoine de St. Exupery

The Biden Administration has announced several goals to be achieved regarding climate change, culminating in Net Zero GHG emissions by 2050 in the US. However, the Administration has not publicly introduced plans to achieve these goals, though the elements of such plans must be in existence.

Certain elements of such plans have begun to become obvious over the past 15 months. The Administration has taken numerous actions to hamper the exploration for and production of oil and natural gas to starve the market for these commodities, including delaying or canceling lease sales and “slow walking” operating permits on existing leases. The Administration has also encouraged the financial markets to deny financing to new fossil fuel projects. The Administration is also preparing new environmental regulations intended to make oil and gas production, transmission and distribution more difficult and expensive.

These actions have resulted in an approximate doubling of fossil fuel prices. The intent of these actions and the resulting increases is to make fossil fuel use less attractive and thus make electric end-use more attractive to consumers and businesses. The most obvious manifestation of this intent is the promotion of electric vehicles of all types, including purchase incentives and federal support for the installation of EV fueling infrastructure. The Administration has actually recommended that people buy EVs to avoid increasing gasoline prices. The recent ban on imports of Russian oil will likely further increase gasoline prices, which have already doubled under the Administration.

The Administration is also actively promoting renewable electricity generation and providing continuing incentives for the construction of wind and solar generation. However, wind and solar generation represent redundant generating capacity, since they require full conventional generation backup in the absence of electric energy storage sufficient to power the grid during periods of low/no wind and solar generation. The conventional backup requirement, combined with dispatch preferences for renewables when available, increases the cost of utility electricity while disincentivizing the operation of the conventional backup generation, which operates at progressively lower capacity factors and thus higher cost per unit of power generated.

Interestingly, the proliferation of renewable generation is increasing electricity costs and thus increasing the cost of the electricity required to recharge the batteries in the EVs being promoted to avoid rising gasoline costs.

Perhaps the most interesting outcome of these Administration actions and the resulting price increases and electric grid reliability issues is the “Blame Game”, in which the Administration denies any responsibility for the results of its actions and points the “finger of blame” at the oil and gas industries and the electric utility industry.

The Administration is joined in pointing the “finger of blame” at the electric utility industry by the developers of renewable generation projects, who assert that the utilities should be responsible for extending transmission lines to their projects and also for providing sufficient electricity storage to meet grid demand during periods of low/no wind and solar generation. That position allows the renewable developers to brag about their low generating costs while blaming the utilities for the increased utility rates resulting from these transmission and storage investments.

By: PragerU

The Precautionary Principle is frequently cited as the justification for actions to halt or retard climate change. This commentary will question the application of the principle to the design of a renewable plus storage electric grid.

The application of the principle to the current US electric grid has centered on the maintenance of a 20% (+/-) capacity reserve margin relative to peak demand. This reserve capacity plus scheduling of generator maintenance during off-peak periods have been very successful in avoiding grid failure. Utility customers with critical loads frequently install standby generators to compensate for distribution or transmission outages caused by adverse weather and accidents.

In recent years, the introduction of intermittent renewable generation and the retirement of conventional generation has tended to reduce capacity reserve margins, as electricity generated by the intermittent renewable generators has displaced electricity generated by conventional sources when the intermittent renewable generators operate. This issue has surfaced in California, which no longer maintains sufficient conventional generation capacity to completely replace the output of intermittent generators when they are unable to generate because of time-of-day or weather conditions. This has resulted in the application of demand-side management programs and in the use of rolling blackouts to avoid grid failure. California also routinely relies on imports of electricity from neighboring states to meet demand.

The critical differences in a renewable plus storage grid with no conventional, dispatchable generation are the very limited availability or complete unavailability of generation sources which are not weather dependent and the unavailability of fossil-fueled standby generators for use in the event of distribution or transmission outages, or worse a grid failure. The unavailability of fossil-fueled standby generators is a particular issue for users with critical loads, such as hospitals.

In a renewable plus storage grid, the dispatchable element is storage. Therefore the Precautionary Principle would appear to require that there be sufficient charged storage capacity with sufficient deliverability to replace the output of the renewable generators over whatever time period the renewable generation is unable to perform or perform at capacity; and, that there be sufficient additional renewable generating capacity to rapidly recharge storage depleted during a renewable generation hiatus in anticipation of the next renewable generation hiatus.

The Precautionary Principle would also appear to require that conventional generating capacity be maintained until sufficient storage capacity and deliverability are installed and operational to replace the conventional generation and sufficient additional renewable generating capacity is available to recharge storage. Renewable generating capacity alone is insufficient to replace dispatchable generation capacity, though it can displace the output of the conventional generation, as is the case today.

While a renewable plus storage grid would require additional capacity to recharge storage, it might not require the type of capacity reserve margin typically used in grids with conventional generation. The individual renewable generators would be much more numerous and of much lower capacity than conventional generators and therefore failure of an individual generator would have far less impact on grid generating capacity.

It would seem that the Precautionary Principle would require that the initial renewable plus storage grid buildout consist of significantly more generating and storage capacity relative to peak demand than the conventional grid it replaces. Experience gained during the early operation of the renewable plus storage grid would help determine the appropriate level of generating and storage capacity and deliverability to be added and maintained as the conversion to an all-electric energy economy proceeds.