Renewables are the wrong target

In responding to climate change national policy often targets the proportion of the electricity generation that will be from renewable sources in 2020 or beyond. These targets are important and, in the absence of any other metric, they are fundamental.

The metric of a renewable generation ratio is however indirect. Coal with carbon capture and storage, when and if the technology is available, is not a renewable generation source. Coal gasification, nuclear power and on-site natural gas co-generation are also non-renewable, yet each is an effective response to climate change.

Each country will have its own options in respect of these alternatives. Each country will assess the benefits and costs of these options in conjunction with renewables differently. In order to ensure that energy supply progresses along the lowest Carbon emissions pathway, the metric should incorporate these types of responses. This metric is the carbon intensity of the supply, measured as CO2e/kWh.

A renewable energy generation ratio provides no guidance on the cleanliness of the electricity supply

Focusing only on the marginal emissions for each kWh produced at generation, the current non-renewable electricity generation facilities have a wide range of carbon intensity - from the 1.4kg CO2/kWh for 'brown coal' to the 0.2kg CO2/kWh for next generation nuclear.

Australia's reliance on coal provides an 860g CO2/kWh carbon intensity - the highest for any OECD country. If Australia were to shift to a 50% renewable electricity generation by 2020, the carbon intensity overall would not be lower than presently exists in The Netherlands, United Kingdom, or Japan - all of whom have negligible renewable generation today.

Significantly, with the possible exception of Poland, the 50% renewable path would result in Australia still having the highest carbon intensity for electricity supply. The weakness of the renewable ratio is that it is a relative one, while the goal is absolute. The sustainability path requires the right targets.

Life-cycle Carbon Cost

The Carbon cost of the power generation is only part of the emissions from energy use. To ensure the investment does contribute to the response to climate change, the evaluation of power generation alternatives should incorporate two additional considerations:

1. Renewable or not, the alternatives have asset life-cycles with very different Carbon cost profiles. That is, the Carbon emissions in the design, build, maintenance, decommissioning and disposal of the power generating asset vary greatly between one alternative and another, with each alternative progressing through these stages over different time scales; and


2. The minimum commercial scale, responsiveness to changes in demand and reliability of each alternative greatly impacts the Carbon costs in the supply at the point of use of the power. Coal fired and nuclear generation operate at a scale resulting in the requirement for long transmission distances, solar power in only available when the sun shines and so on. The infrastructure to ensure reliable transmission and supply can cost more in Carbon emissions than the generation itself.

The inclusion of these two considerations challenges any response to climate change as no alternative is the right one in every situation. The carbon intensity at point of use of an on-site natural gas generator is lower than for a utility scale photo-voltaic solar generator 500kms away. The key is to consider energy not in terms of how it is generated, but where and when it is used.

The response to climate change is a journey that we have only just started. Today policy is focusing on renewables. Certainly, renewables are needed as part of the energy supply mix but only where and when they lower the carbon intensity of the energy use (not supply) over the life-cycle of the generation and energy transport (transmission and control) assets.

The next step is to shift the focus to incorporate factors such as the advantages of localisation of energy supply, the disadvantages of power conversion, the gains and the penalties in low emission non-renewable sources. This step is the targeting of a new metric, the carbon intensity at point of use – a metric that applies to all energy use.

Good for one is not good for the many

Many jurisdictions are encouraging the installation of residential small scale solar power systems. The economics for this appear simple - invest in the installation now and, for the next 25 years, reduce the electricity demand of the household on the electricity grid. Ignoring any government assistance that may be available, the savings in electricity suggest a payback in as little as 4 or 5 years for some electricity buyers. In fact, even when excluding the effect of the expected rise in electricity prices over the coming decade, a typical installation would save more than $10,000 over its lifetime. This is clearly good for the electricity user, but is it sustainable?

There is no relationship between monetary savings and a reduction of carbon emissions. Unfortunately, any currently proposed pricing of Carbon will not fix this.

In terms of responding to climate change, the scenario still appears to make sense. Every kWh of electricity bought is usually considered to be at least ½kg of Carbon. A single domestic solar panel can produce over 5,000 kWhs over the expected minimum 25 year life - thus providing a 2.5t saving of Carbon. Every little bit helps, right? Not quite.

Life-cycle Carbon Cost

The weakness in the approach taken above is that it is only a snapshot of the life-cycle of the solar panel. A solar panel does not appear on the roof of a house without a carbon cost. No agreed standard for the assessment of this cost exists and there is substantial variation in the data available for considering it. Nevertheless, considering the entire industrial process, the panel will have cost at least 1t of Carbon to manufacture, supply and install. In addition, in disposal, albeit hopefully more than 25 years away, it will cost a further 200+kg of Carbon.

Therefore, the panel has a debt of 1.2+t of Carbon to repay, effectively halving any potential benefit. However, before considering the benefit, let's look back at two assumptions in this scenario. Firstly, a solar panel will provide peak power throughout operation and secondly, the Carbon intensity of the offset electricity will remain constant.

Solar performance is very installation dependent

The output of a solar panel is dependent upon many factors - the amount of hours of sun the installation location receives, how closely the panel is pointed to the mid-arc point of the sun passage on the solar equinox and even the ambient temperature. There are also losses in converting the DC power output to a regulated AC domestic supply, losses due to the inability to use the generated power when it is generated and, for most panel designs, losses due to a shadow across just 10% of the surface shutting off the power generation. The result is that the actual electricity offset can be less than 2,000kWh.

Is all mains electricity supply Carbon intensive?

The Carbon intensity of electricity is dependent on the method of its generation. Generally, the worst is brown coal and the best is hydroelectric or nuclear (wind and solar usually have a higher intensity than either of the latter sources when considered in life cycle terms). The on going COP or post-Kyoto discussions provide indication for encouraging energy policy responses to climate change. These policies will guide and accelerate a lower carbon intensity for electricity supply worldwide. This means that the average carbon intensity over the next 25 years is not the ½kg per kWh generally assumed but more likely less than half this level (many supply environments today can already be less than 150g per kWh).

In terms of considering many real world installations over a 25+ year life neither of the former assumptions hold. Certainly, the benefit can still be a net saving but one sensitive to site specific factors. Our analysis suggests the benefit is rarely more than 1t of Carbon per solar panel even in relatively sunny carbon intense energy markets as Australia. Significantly, even before any further 'greening' of the electricity supply in this coal rich country, there is a negative Carbon balance for installations in its most southern state due to the combination of that state's use of hydroelectric supply and its distance from the equator. Negative Carbon balances can also be found in certain parts of the United States, Japan and even China, as well as all grid connected residences of France, Iceland, and Brazil.

Every saving counts and the value of this approach to climate change should not be lost. However, caution is required as there is a significant risk for misplaced investment due to the perceived efficiency improvements and financial return available.

What is carbon economics?

Economics is the defined as the study of how people use their limited resources in an attempt to satisfy unlimited wants. Using this as a base, Carbon Economics can be defined as:

The study of how individuals, society, business, government and nations address the limited capacity of the planet to sustainably absorb greenhouse gases in an attempt to maintain and improve their quality of life.

That is, the limited resources become how much greenhouse gas the planet can absorb without changing the climate and the unlimited wants become the quality of life. Perhaps the more accurate term for this is Greenhouse Gas Economics, but as the main greenhouse gas by volume is carbon dioxide, the label Carbon Economics seems more clear.

The term is not new, however it does not have a fixed definition. This is counterproductive and so this blog seeks to lock down a meaning to support better understanding and clearer communication.

It isn't about money

The key departure of our approach from the general discussion on this subject is that we do not monetise greenhouse gases. Carbon Economics is not about the trading of carbon credits; or the investment analysis for the projects that lower the carbon footprint of an industry sector; or analysis of the effect the pricing of carbon has on the cost of living. These are important considerations and form part of the study within Carbon Economics. They inform the policy to solve the unexpressed problem (which will be covered in later posts). They do however miss the point.

The wants are not a product or service and the resource is not money (as is the typical situation in economics). The resource is an "overdrawn account" against the capacity of the planet to absorb greenhouse gases and the want is avoiding the impact that increasing or even maintaining the "overdrawn account" will have on the quality of life. There is no money involved at this level of the study.

Why does this departure matter?

Money has a meaning of its own, a meaning that is not equal between people. Money is not a common global mechanism for value - US$1 does not buy the same amount of an equivalent product or service globally even excepting for local taxes and similar distorting influences. Money is not a single item - we don't use just one currency globally.

Carbon (measured as CO2e) means little to anyone today. Unfortunately, when it will mean something most people will see it as the harbinger of personal catastrophe (the loss of home or a lack of drinking water, etc). Carbon has the same impact to the climate regardless of where on the planet it is released and a unit of carbon is still a unit of carbon. Carbon isn't like money.

Hence we might conclude that Carbon is a commodity, simply a new product to price. However all commodities have a different value depending on where on the planet they are and involve the exchange itself of the commodity or right to the commodity. Certainly if we monetise Carbon we may have something that is tradeable, but the distinction should be made that we are not trading the carbon itself, but a contract about it. Carbon is no more a commodity than an insurance contract is.

The need for new tools

More than a century of modern economic theory has provided a great many tools to analyse and compare the value of money over time and the value of alternatives for how money is used. These theories and tools are part of our ability to have increased the quality of life so significantly for so many over the same time period.

A fundamental premise for these tools is that the value of money changes over time due to a single factor - inflation. This provides for money spent or earned in the future to be evaluated in terms of the meaning of money today by discounting it back in time. There are, of course, the different perceptions for the need to spend or the chance to earn in the future. This difference gives rise to dissimilar valuations and much of the trade seen in markets. This apparent variable for the value of money, or more correctly what it can purchase of be invested in, is an emergent outcome from people working with uncertainty regarding the future, not an outcome from the money itself.

The value of Carbon changes over time due to (at least) two factors:

1. The amount of carbon emissions in a given year relative to the sustainable level; and
2. The ease with which the emissions can be addressed.

The first factor is conceptually the inflation of Carbon. The more our emissions depart from the sustainable level, the more valuable the avoidance or absorption of the Carbon. However, it is a significantly more dynamic consideration than monetary inflation as most sources of Carbon remain in the atmosphere impacting the climate for more than a century (so the sooner the emissions stop happening, the less accumulative the stock of Carbon in the atmosphere and thus the lower the effect of Carbon on the climate).

The second factor has no conceptual equivalent as it relates to a change in the relationship for the supply of Carbon. The mechanism for the supply of money does not change, the government of a country mints notes and coins, banks distribute them and money is created through the payment of interest and trading of risk (this is an overly simplistic picture, however it is illustrative).

Over time technological development and production scaling will change the relative ease with which the emitting of Carbon can be avoided or absorbed from the atmosphere. This is a key variable for the consideration of carbon emissions in different time periods.

Consider the ability to have zero emission private transport. Today it is impossible, as emission free power to mobilise a car is not available. In 2050 it will be available and most likely at a price that is competitive with less Carbon friendly options. This variation in supply availability makes the Carbon in 2050 less valuable than in prior periods. That is, the harder it is to do something about it, the more valuable doing something is.

This difference means that new tools are required to support decisions about Carbon and the study to develop them and consider their impact is the core of Carbon Economics.