I keep seeing a misconception that transmission lines are made out of copper.

For the vast majority of lines (especially overhead), that's not the case.

Most power lines are made from a steel core wrapped with aluminum conductors.
(that's why power lines look silvery and not coppery)

Steel provides the strength, and aluminum provides the conductivity.
(they both provide some of each but that's primarily how it works)

But isn't copper more conductive than aluminum?

For the same cross sectional area, aluminum is only about 60% as conductive as copper, but it's also only 30% as dense as copper.

For the same mass of metal, aluminum is about twice as conductive as copper.

Copper is better when you're space constrained (like in an electric motor), but aluminum is better when you're weight constrained.

Aluminum isn't just a cost saving measure (although it does cost 1/4th as much per kg). For a lot of applications, aluminum is actually better than copper. I posted this without noticing that the right side of the diagram is mislabeled.

Here’s a diagram without the confusion, and an extra bonus.

Advanced conductors use a lightweight, high-strength core. That frees up weight for more aluminum conductor, while staying within the limits of the transmission towers.

Advanced conductors can be a way to upgrade transmission capacity without needing to build new towers or acquire new right of way.

They’re not a miracle fix for everything, but they can be a really useful tool if you’re facing urgent constraints.

The physics of heat transfer are way cooler than you think.

If we designed homes with them in mind, they'd be a lot more resilient and energy efficient, and people would be a lot more comfortable.

Insulation standards and HVAC systems are designed around maintaining the air temperature inside a building, but air temperature is only a tiny slice of the picture.

In typical conditions, only ~15% of the human body's heat loss is from convection.

~60% is from radiation, and ~20% is from evaporation (breathing and sweating).

Your body glows like a light bulb with infrared radiation. You are constantly emitting infrared radiation into the environment and absorbing infrared radiation from the environment.

Radiative power scales with the 4th power of temperature, so even small changes in temperature result in large changes in heat flux.

If your skin temp is 34°C (93.2°F), you emit 505 W/m^2.

A wall at 10°C (50°F) emits 364 W/m^2 while a wall at 40°C (104°F) emits 545 W/m^2.

Your body is ~100 W and ~2 m^2. You need a net cooling of ~50 W/m^2 to maintain your body temperature.

If you weren't constantly bathed in infrared radiation, you'd quickly lose heat to the environment. If you're surrounded by hot surfaces, you can be baked by infrared even if the air temperature is low.

The temperature of the walls, ceiling, and floor is more important than temperature of the air.

Underinsulated surfaces can be cold even when the air is warm, and hot even when the air is cold. This (and humidity) is why your house at 70°F doesn't feel the same in the winter and the summer.

Doubling the amount of insulation in a home cuts the energy required to maintain a given air temperature in half, but it also cuts the differential between the temperature of the walls and the air.

With better insulation, not only do you not need as much energy to maintain the same air temperature, you don't even have to maintain the same air temperature.

Air conditioning can reduce humidity, but most air conditioners can't intentionally control humidity, and most HVAC system have no way to increase humidity.

Better control over humidity reduces the temperature differential your house has to maintain with the outside to provide the same heat transfer for the people inside.

Having air that's not overly dry in the winter means it doesn't have to be as warm to be comfortable. Having air that's not overly humid in the summer means it doesn't have to be as cold.

The goal is to maintain human body temperature, not air temperature. Radiation and evaporation make up most of the heat transfer.

Looking only at air temperature completely misses the big picture. We underinsulate our homes and don't provide adequate control over the aspects that are most important for comfort.

Insulation provides a much larger efficiency benefit than you'd expect from a simple Manual J calculation. That's compounded by the fact that the economic value of that energy savings is far larger than flat volumetric pricing indicates. (because insulation provides the most benefit in extreme conditions where capacity is constrained and prices are high)

Heat and cooling are the majority of energy use in homes, and the vast majority of energy costs.

Real consideration of the physics of heat transfer and the economics of energy systems in the way we design homes and HVAC systems would provide massive economic benefits.
We really need to update building codes. >2" of continuous exterior insulation should be standard everywhere.

The economic benefits are huge, and we're currently subsidizing inefficiency with distorted price signals.

Beyond energy efficiency and resilience in extreme weather, exterior insulation is extremely beneficial for building longevity and indoor air quality.

Cold condensing surfaces promote mold growth and rot.

We can solve all of this if we just build better buildings.

1. We CAN cut consumer energy costs in half, but drilling alone is not going to be enough.

We need much more radical changes to our energy system.

If natural gas were free tomorrow, consumers would still be paying 85% as much as they are right now because most of the cost of gas is delivery. 2. American households spend around $2,000/year on energy for their homes and another $2,000/year on energy for their cars.

To radically cut energy costs, we need to radically change the way energy is produced, delivered, and used.

1. Why would you want a solar fence? Don't solar panels need to face the Sun?

Vertical bifacial panels will give good output on an annual basis in any orientation.

They're especially suited for winter production. 2. Vertical bifacial panels capture the low winter Sun.

Snow doesn't collect on top of them, and they capture light reflecting off of snow on the ground.

1. I don't think people realize just how expensive electricity used to be.

Real electricity prices are HALF of what they were in 1960.

The "good old days" of "cheap coal" is just cheap propaganda. 2. Money printing made nominal prices go up - not new technology.

Real electricity prices are roughly 1/10th what they were a century ago.

1) Richard Smalley was right.

The Nobel Prize winning chemist had incredible foresight about the challenges of the 21st century

He realized that a single issue was the key to addressing our biggest problems - energy 2) Smalley's list of humanity's top 10 problems organized the issues hierarchically

- energy solves water (desalination)
- energy + water solves food (fertilizer + irrigation)
- etc.