Why don't we use weights to store energy?
Вівторок, 24 Січень 2017 19:06![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png)
Q: Why don't we use weights to store energy?
Now, how much energy can it store? This is given by potential energy formula E=mgh, thus E=100kg⋅9.8m/s2⋅10m=9.8kJ≈2.7Wh.
For comparison, a single AA-sized battery stores about 2Wh of energy.
dotancohen: Does that imply that a single AA-sized battery with a suitable motor and gearing could lift four 25 KG suitcases to my third-floor apartment?
Luaan: Ignoring a few complications and efficiency losses, yup, almost.
One of the main reasons why we haven't switched to clean energy is the lack of efficient storage methods - But, why aren't we using dead weights to store energy and draw it back later when needed? As an example of what I mean:
Now, how much energy can it store? This is given by potential energy formula E=mgh, thus E=100kg⋅9.8m/s2⋅10m=9.8kJ≈2.7Wh.
For comparison, a single AA-sized battery stores about 2Wh of energy.
dotancohen: Does that imply that a single AA-sized battery with a suitable motor and gearing could lift four 25 KG suitcases to my third-floor apartment?
Luaan: Ignoring a few complications and efficiency losses, yup, almost.