A radical idea to get a high-renewable electric grid: Build way more solar and wind than needed

著名的发明家埃德温·兰（Edwin Land）说，“这并不是我们需要新的想法，而是我们需要停止有旧的想法。”他似乎在告诉我们，解决方案就超出了我们的旧思维习惯。

世界各地的城市，各州和国家都致力于清洁可再生能源的高水平（甚至100％）的清洁能源经济体。仅在纽约州，有四个竞争法案针对50％至100％的可再生能源在2040年之前或之前。

实际上，只有两个可再生能源足够大（PDF）to meet these very high-penetration objectives on the supply side in the United States — solar (by far) and wind.

然而，两者都是可变资源，由天气以及日常周期和季节性周期驱动。因此，它们必须“牢固”（能够按需交付能力），才能替换可以根据需要派遣的化石资源。基于我们的研究，我们认为这种公司的权力转变不仅可能是可能的，而且如果我们不再有旧的想法，它也是负担得起的。

一个根深蒂固且非常普遍的想法（可能是历史上可再生能源价格高的结果）是，必须在生成时出售可再生资源产生的所有功率。丢弃可用风能或太阳能输出的想法是厌恶的，当这些来源的生产超过电网所能接受的产品时，就会强加于电力生产商。

这个古老的想法忽略了一个基本命题：过度尺寸和主动减少风和太阳能. However counterintuitive, a study our colleagues and we conducted shows that these steps are the key to the least expensive path to an electric grid powered largely by solar and wind.

Weighing against energy storage

The reasoning behind overprovisioning solar and wind is straightforward:

• 储能当太阳不发光或风不会吹来时，填充可再生能源可变性所需的一种基本要素。这些差距包括日期内的时间，例如白天和黑夜的高峰需求时间，更重要的是，持续的低日期或低风速条件的较大的多日和季节性差距。对于存储，网格操作员 - 确保电源在白天上升和下降时的需求与需求相匹配的组织 - 通常依靠水库pumped hydro或者，在较短的时间内，电池。

• 存储越来越便宜，但是即使假设最乐观的长期成本预测，我们的研究也使我们得出结论，由于多日和季节性差距的规模，仅将存储单独应用于牢固的风能或太阳能方面都将保持昂贵。风和太阳能也变得越来越便宜，特别是太阳能，到建筑物越来越负担得起的地步。即使来自风和太阳能发电机的输出基本上被倾倒或“限制”并且未馈入网格，这也是正确的。

• Oversizing reduces production gaps because more energy output is available during periods of low solar and wind availability. Overbuilding also reduces storage requirements.

‘Firming’ with overcapacity

Today, the current regulatory practice for solar and wind-generated electricity favors maximizing production at all times. The companies that operate these facilities seek to sell all their output at the highest prices, so curtailing output is seen as a revenue loss.

这种旧的操作想法抑制了依靠太阳能和风作为牢固的按需来源的过渡，因为仅在可用时才使用它们的所有输出。这种方法还将可再生能源保持在边缘。

That old operational idea inhibits the transition to relying on solar and wind as firm, on-demand sources. ... This approach also keeps renewable energy at the margin.

How would a grid with overbuilt solar and wind resources work in practice? Let’s say the operator of a regional electricity grid needs X megawatt-hours/day to meet demand. Today the solar farms in that region can meet or exceed this demand only on days of the highest production, such as clear days in the summer. On other days, the production gaps are met by storage.

By contrast, when the solar resource is oversized, that solar generator can meet the X MWh/day demand more days of the year and there are fewer gaps — hence fewer times that energy storage is need to fill the gaps.

Once firmed up through a combination of overprovisioning and storage, variable renewable energy resources become effectively dispatchable — able to provide power when as needed — and functionally equivalent to traditional power plants. In this way, renewables can replace these generators without major grid reengineering.

Our team has modeled a高极性和过度建筑溶液（PDF）for the not particularly sunny state of Minnesota. The goal was to determine the least costly combination of grid-connected solar, wind and storage necessary to provide round-the-clock, year-round energy services.

The study demonstrates that overcoming the natural variability of solar and wind can be accomplished at costs below current grid costs (so-called "grid parity") by overbuilding solar and wind resources and adopting a grid operating strategy of allowing about 20 percent to 40 percent curtailment of excess energy generation. Energy storage is also used in our model, but the superior economics directly result from substituting excess curtailable generation for more expensive storage.

克服太阳能和风的自然变异性可以通过过度建造太阳能和风能来实现，并采用允许20-40％缩减的网格操作策略。

A legitimate question to ask is what would be the area required for a full deployment of oversized solar PV. For Minnesota, in the most extreme 100 percent PV generation scenario assuming oversizing by a factor of two — or doubling the solar needed to meet current demand — this area would amount to 435 square miles, assuming solar panels with state-of-the-art efficiency of 20 percent. This area represents不到该州的1％种植的农作物和中等密度的城市化空间的一半。

调整散装电网如何运行

除了超大，削减和存储优化外，已经完成了几种操作和计划实践，还将进一步提高高极性网格的价值和性能，并通过最小的破坏来促进其实现。他们包括：

• Exploiting the complementary performance and variable operating profiles of solar and wind. In most locations wind and solar have complementary diurnal and seasonal production profiles — wind higher at night and in winter, PV higher in the daytime in summer.

• Using demand management — the practice of reducing power use at electricity customer locations — as a way to minimize supply and demand gaps.

• Enabling grid operators to have authority over renewable energy siting and production management within their regions so that decisions over when curtailment occurs or storage is applied are made on a regional basis to minimize gaps in supply and demand.

当可变的太阳能发电非常昂贵时，最大化可再生能源生产和避免限制的态度变得有意义，而通气解决方案甚至更昂贵。但是，从交钥匙太阳能，网格管理和存储成本中的最新和预测减少正在改变最佳解决方案集，从过度建筑太阳能开始。

Marc Perez, senior researcher at Clean Power Researcher, who wrote his dissertation at Columbia University on this subject, contributed to this article. Morgan Putnam, VP of Solar Analytics at REsurety, also contributed.