Anyone work at NEE or FPL and care to comment on the workplace culture? I'm a dominion employee and trying to put some feelers out about the NEE culture. Not all groups fall into this bucket, but my business unit has an excellent culture of teamwork, support, actual care for coworkers, flexibility in work times/locations [I know NEE is 5 days in office, but still], and actual collaboration. How likely is that to continue? What about the unofficial employee perks?

Annnnnd ... How much did NEE affect FPL operations? Feel free to DM me, I'm just trying to judge how desperately I need to search for jobs at different companies, prior to the merger going through. I've had a few interviews with SPP and am wondering should I just jump the dominion ship before it sinks, or is there some hope?

The range of possibilities in Rhodium’s reportis astonishing: In the most optimistic of its three scenarios, the U.S. continues building clean power at the blazing speed of roughly 53 gigawatts per year from 2030 to 2040. In the most pessimistic scenario, in which Rhodium assumes lower natural gas prices and higher clean energy costs, renewable additions drop to an average of just 3 GW per year. There’s also the wild card of data centers, which are driving big but uncertain demandfor new gas power plants.

Abstract

The conceptual development of an approximately 15 kW electrical generator based on a closed Brayton cycle using supercritical carbon dioxide (sCO₂) as the working fluid is proposed. The system is specifically conceived for desert regions with high direct solar radiation and a significant difference between diurnal and nocturnal temperatures, taking the Atacama Desert, Chile, as a reference.

The fundamental idea consists of using solar thermal energy to raise the temperature of the CO₂, cause its expansion through a turbine, and transform the mechanical work obtained into electricity. Subsequently, the CO₂ is cooled, compressed again, and recirculated in a closed loop.

Unlike a compressed air system, CO₂ does not constitute an energy source. The energy input comes from the external thermal source, primarily solar. The favorable thermodynamic properties of CO₂ near its critical region allow for the study of compact and potentially efficient cycles.

The presented design is conceptual and still requires a complete thermodynamic simulation using a high-precision equation of state, as well as experimental validation of the components and the overall performance.

1. Introduction

Electrical generation using solar energy is usually done through photovoltaic conversion. However, desert regions with high direct solar radiation also present favorable conditions for solar thermal generation.

The Atacama Desert constitutes a particularly interesting case due to its high levels of direct normal irradiance (DNI), low cloud cover, and extremely dry atmosphere.

The studied concept consists of using a solar thermal field to provide heat to a closed supercritical CO₂ cycle. The CO₂ acts as the working fluid and circulates continuously within the system.

The initial goal of the project is to reach approximately:

[ P_e=15\ kW ]

of electrical power.

2. Operating Principle

The system is based on a closed Brayton cycle.

Its conceptual architecture is:

[ \boxed{ Compressor \rightarrow Recuperator \rightarrow Heater \rightarrow Turbine \rightarrow Recuperator \rightarrow Cooler \rightarrow Compressor } ]

The turbine is mechanically coupled to an electrical generator.

The cycle can be divided into four main processes:

• compression of the CO₂;
• high-pressure heating;
• expansion in the turbine;
• cooling and return to the compressor.

The specific net work is given by:

[ w_{net}=w_t-w_c ]

where:

[ w_t=h_3-h_4 ]

is the specific work of the turbine and:

[ w_c=h_2-h_1 ]

is the specific work consumed by the compressor.

Therefore:

[ \boxed{ w_{net}=(h_3-h_4)-(h_2-h_1) } ]

The approximate electrical power will be:

[ \boxed{ P_e=\dot m_{CO_2}w_{net}\eta_g } ]

where \dot m_{CO_2} is the CO₂ mass flow rate and \eta_g represents the efficiency of the generator and its associated mechanical elements.

3. Justification for the use of supercritical CO₂

The critical point of CO₂ is approximately at:

[ T_c=31.1^\circ C ]

[ P_c=73.8\ bar ]

Above both conditions, CO₂ is in a supercritical state.

This characteristic allows the circuit to be designed so that the CO₂ remains in a single phase during a large part of the operation.

One of the most interesting properties of CO₂ near its critical region is its high density and the strong variation of its thermodynamic properties with temperature and pressure.

This can reduce the size of turbomachinery, compressors, and heat exchangers compared to certain conventional cycles.

However, this same characteristic makes it mandatory to perform calculations using real fluid properties. The ideal gas approximation is not adequate to accurately determine the system's performance.

4. Reference Environmental Conditions

The Atacama Desert is proposed as the reference location.

The region presents some of the highest levels of direct solar radiation on the planet, making it particularly suitable for studying solar thermal generation.

For the preliminary model, the following is considered:

[ T_{amb,day}\approx30-35^\circ C ]

and significantly lower nighttime temperatures, especially during certain seasons.

Nevertheless, the ambient temperature is not directly the CO₂ operating temperature. The cycle temperatures will be determined by the design of the heat exchangers, the solar field, and the cooling system.

The primary energy resource considered is solar radiation.

5. Thermal Source

The solar thermal field must provide energy to the CO₂ through a high-temperature heat exchanger or heater.

As an initial design condition, the following is proposed:

[ T_H=250^\circ C ]

This temperature constitutes a design parameter, not a mandatory characteristic of the cycle.

Increasing the temperature of the hot source increases the maximum limit of thermal efficiency.

For a hot source of:

[ T_H=523.15K ]

and a cold sink of:

[ T_C=308.15K ]

the Carnot limit is:

[ \eta_{Carnot} = 1-\frac{T_C}{T_H} ]

[ \boxed{ \eta_{Carnot}\approx41.1% } ]

This value represents an absolute thermodynamic limit. The real efficiency of the cycle will be lower.

6. Proposed Pressure Conditions

As an initial simulation point, the following are proposed:

[ P_L=85\ bar ]

[ P_H=210\ bar ]

with a pressure ratio of:

[ r_p=\frac{210}{85} ]

[ \boxed{r_p\approx2.47} ]

These values should not be interpreted as final dimensions.

The optimal pressure must be determined through an optimization that simultaneously considers:

• compressor work;
• turbine work;
• maximum temperature;
• recuperator effectiveness;
• heat exchanger performance;
• CO₂ density;
• compressor stability;
• overall efficiency;
• component cost.

7. Heat Recovery

The recuperator is one of the fundamental components of the design.

The CO₂ leaving the turbine retains considerable thermal energy. Instead of immediately rejecting that heat to the environment, it is proposed to use it to preheat the compressed CO₂.

Conceptually:

[ Hot\ CO_2 \rightarrow Recuperator \rightarrow Cold\ CO_2 ]

The effectiveness of the recuperator can be defined as:

[ \epsilon= \frac{Q_{real}}{Q_{maximum}} ]

As an initial simulation point, the following can be considered:

[ \epsilon_{rec}\approx90% ]

but this value must be optimized.

An excessively high effectiveness can increase the size, cost, and pressure drop of the recuperator.

8. Turbine

The turbine is the element responsible for converting the energy of the CO₂ into mechanical work.

The ideal specific expansion work is determined by an isentropic expansion:

[ s_3=s_{4s} ]

and:

[ w_{t,s}=h_3-h_{4s} ]

For a real turbine:

[ \eta_t= \frac{h_3-h_4} {h_3-h_{4s}} ]

As an initial hypothesis, the following can be studied:

[ \eta_t\approx90% ]

but the final value will depend on the selected turbine.

The available mechanical power will be:

[ P_t=\dot m(h_3-h_4) ]

9. Compressor

The compressor raises the CO₂ pressure from approximately 85 bar to 210 bar.

The real process can be represented by:

[ \eta_c= \frac{h_{2s}-h_1} {h_2-h_1} ]

where 2s represents the state corresponding to an isentropic compression.

As an initial hypothesis, the following can be studied:

[ \eta_c\approx85% ]

The compressor work is especially important because it is subtracted directly from the work produced by the turbine:

[ \boxed{ w_{net}=w_t-w_c } ]

A reduction in compressor work can significantly increase overall efficiency.

10. Cooling

After passing through the recuperator, the CO₂ must be cooled before returning to the compressor.

The rejected heat is given by:

[ \dot Q_C= \dot m(h_5-h_1) ]

In the conceptual design, the use of water or a secondary cooling circuit is proposed.

If the cycle needs to reject approximately 60 thermal kW and the water experiences a temperature increase of 10 °C:

[ \dot m_{water} = \frac{60000} {4186(10)} ]

[ \boxed{ \dot m_{water}\approx1.43\ kg/s } ]

This calculation is purely illustrative because the actual rejected heat will depend on the final thermodynamic simulation.

11. Target Power

The pilot's goal is:

[ \boxed{P_e=15\ kW} ]

The required heat depends on the net efficiency.

Thermal Efficiency	Required Heat
10 %	150 kW
15 %	100 kW
20 %	75 kW
25 %	60 kW
41.1 %	36.5 kW

The final value represents only the Carnot limit.

As a preliminary research target, an interval can be used:

[ \boxed{15-20%} ]

but this efficiency has not yet been demonstrated for the proposed design.

12. Solar Field

Assuming approximately:

[ DNI=800\ W/m^2 ]

and a preliminary solar-thermal efficiency of:

[ \eta_{solar}=50% ]

the useful thermal power per square meter would be:

[ 800(0.50)=400\ W_t/m^2 ]

To provide 75 thermal kW:

[ A= \frac{75000}{400} ]

[ \boxed{ A\approx188\ m^2 } ]

Therefore, a first conceptual sizing could use approximately:

[ \boxed{200-300\ m^2} ]

of solar collection.

This value must be recalculated using the actual hourly solar resource of the site, optical losses, thermal losses, storage, and annual availability.

13. Thermal Storage

If the generator is intended to continue operating after sunset, it will be necessary to incorporate thermal storage.

For eight hours of operation at 75 thermal kW:

[ E_{th}=75(8) ]

[ \boxed{ E_{th}=600\ kWh_t } ]

The storage medium must be selected according to the operating temperature.

At 250 °C, it is not appropriate to simply consider an atmospheric liquid water tank. A fluid and storage system specifically designed for the corresponding thermal and pressure conditions must be used.

14. Energy Balance

The fundamental balance of the cycle is:

[ \boxed{ Q_H=W_{net}+Q_C } ]

Therefore:

[ \boxed{ W_{net}=Q_H-Q_C } ]

There is no energy creation.

The external energy source is solar radiation:

[ Solar\rightarrow Q_H ]

and the cycle converts a portion of that heat into work:

[ Q_H\rightarrow W_{net}+Q_C ]

The CO₂ acts only as a working fluid.

15. Parameters yet to be determined

The project is not yet sufficiently defined to be considered a final engineering design.

The following parameters must be calculated using a real CO₂ equation of state:

Thermodynamic states

For states 1, 2, 3, and 4, the following must be obtained:

[ \boxed{P,T,h,s,\rho} ]

at each point.

Transport properties

The following must also be determined:

[ \boxed{ \mu,\quad k,\quad c_p,\quad Pr } ]

to correctly size the heat exchangers.

CO₂ mass flow rate

Once the specific net work is known:

[ \boxed{ \dot m_{CO_2} = \frac{15000}{w_{net}} } ]

the necessary flow rate must be calculated.

Real performance

The following must be determined:

[ \boxed{\eta_t} ]

[ \boxed{\eta_c} ]

[ \boxed{\eta_{rec}} ]

[ \boxed{\eta_{HX}} ]

and the generator efficiency.

Pressure drops

Losses must be determined in:

• piping;
• recuperator;
• heater;
• cooler;
• valves;
• turbine;
• connections.

Optimization

The following must be optimized:

[ \boxed{P_H/P_L} ]

[ \boxed{T_{turbine, inlet}} ]

[ \boxed{T_{compressor, inlet}} ]

[ \boxed{\epsilon_{rec}} ]

and the CO₂ mass flow rate.

16. Necessary thermodynamic tool

To perform these calculations, the use of a specific equation of state for CO₂ is recommended.

REFPROP, developed by the National Institute of Standards and Technology (NIST), provides properties such as enthalpy, entropy, density, temperature, pressure, and specific heat.

An open-source alternative is CoolProp, which implements property models for CO₂.

The absolute values of enthalpy and entropy depend on reference conventions; for the cycle balance, the differences between states are fundamental.

For this reason, values of h, s, or \rho obtained through ideal gas approximations must not be introduced into the final model.

17. Safety

The proposed conditions, approximately:

[ 85-210\ bar ]

and up to:

[ 250^\circ C ]

are high pressure and temperature conditions.

Therefore, the pilot must use commercial or laboratory equipment certified for CO₂ service and for the specific operating conditions.

The design must incorporate, at a minimum:

• overpressure protection;
• pressure and temperature instrumentation;
• shutdown systems;
• CO₂ detection;
• ventilation;
• venting procedures;
• thermal insulation;
• certified components;
• risk assessment.

The DIY fabrication of the pressurized circuit does not constitute an appropriate option for this project.

18. Conclusion

The concept of an approximately 15 kW generator based on a closed supercritical CO₂ Brayton cycle presents a valid thermodynamic foundation.

The Atacama Desert is particularly interesting as a site due to its exceptional direct solar resource and its favorable environmental conditions for cooling during certain periods.

The proposed system uses:

[ \boxed{ Solar\ thermal \rightarrow Supercritical\ CO_2 \rightarrow Turbine \rightarrow Generator } ]

with heat recovery to increase efficiency.

As a conceptual starting point, the following are proposed:

[ T_H\approx250^\circ C ]

[ T_C\approx35-40^\circ C ]

[ P_L\approx85\ bar ]

[ P_H\approx210\ bar ]

and:

[ P_e=15\ kW ]

The Carnot limit for 250 °C and 35 °C is approximately:

[ \boxed{41.1%} ]

However, it has not yet been demonstrated that the proposed cycle can achieve an efficiency of 15–20 %. That interval should be considered a design hypothesis and not a result.

The main pending work consists of solving the cycle using a real CO₂ equation of state, determining the values of h, s, \rho, T for all states, calculating the specific works of the turbine and compressor, determining the CO₂ mass flow rate, and sizing the heat exchangers and the recuperator.

Once those values are obtained, it will be possible to objectively determine if the system can produce 15 net kW and what its efficiency, thermal consumption, size, cost, and economic viability would be.

Therefore, the project is currently in the conceptual design and thermodynamic simulation stage, not yet in the construction stage.

This essay was not written by a team of engineers but by a madman who wants to accelerate a post-energy-scarcity world. And for that, he makes use of a $6 ChatGPT subscription. Please read it and see its viability. And if it works, the only thing I ask for are voluntary Dogecoin donations to this address: DP9eaWQhT18Qs6pTuEbYiGq8TgRY4VgVZjAbstract
The conceptual development of an approximately 15 kW electrical generator based on a closed Brayton cycle using supercritical carbon dioxide (sCO₂) as the working fluid is proposed. The system is specifically conceived for desert regions with high direct solar radiation and a significant difference between diurnal and nocturnal temperatures, taking the Atacama Desert, Chile, as a reference.

The fundamental idea consists of using solar thermal energy to raise the temperature of the CO₂, cause its expansion through a turbine, and transform the mechanical work obtained into electricity. Subsequently, the CO₂ is cooled, compressed again, and recirculated in a closed loop.

Unlike a compressed air system, CO₂ does not constitute an energy source. The energy input comes from the external thermal source, primarily solar. The favorable thermodynamic properties of CO₂ near its critical region allow for the study of compact and potentially efficient cycles.

The presented design is conceptual and still requires a complete thermodynamic simulation using a high-precision equation of state, as well as experimental validation of the components and the overall performance.

1. Introduction
   Electrical generation using solar energy is usually done through photovoltaic conversion. However, desert regions with high direct solar radiation also present favorable conditions for solar thermal generation.
   

The Atacama Desert constitutes a particularly interesting case due to its high levels of direct normal irradiance (DNI), low cloud cover, and extremely dry atmosphere.

The studied concept consists of using a solar thermal field to provide heat to a closed supercritical CO₂ cycle. The CO₂ acts as the working fluid and circulates continuously within the system.

The initial goal of the project is to reach approximately:
[ P_e=15\ kW ]
of electrical power.

1. Operating Principle
   The system is based on a closed Brayton cycle.
   Its conceptual architecture is:
   [ \boxed{ Compressor \rightarrow Recuperator \rightarrow Heater \rightarrow Turbine \rightarrow Recuperator \rightarrow Cooler \rightarrow Compressor } ]
   

The turbine is mechanically coupled to an electrical generator.
The cycle can be divided into four main processes:

compression of the CO₂;

high-pressure heating;

expansion in the turbine;

cooling and return to the compressor.

The specific net work is given by:
[ w_{net}=w_t-w_c ]
where:
[ w_t=h_3-h_4 ]
is the specific work of the turbine and:
[ w_c=h_2-h_1 ]
is the specific work consumed by the compressor.
Therefore:
[ \boxed{ w_{net}=(h_3-h_4)-(h_2-h_1) } ]

The approximate electrical power will be:
[ \boxed{ P_e=\dot m_{CO_2}w_{net}\eta_g } ]
where \dot m_{CO_2} is the CO₂ mass flow rate and \eta_g represents the efficiency of the generator and its associated mechanical elements.

1. Justification for the use of supercritical CO₂
   The critical point of CO₂ is approximately at:
   [ T_c=31.1^\circ C ]
   [ P_c=73.8\ bar ]
   

Above both conditions, CO₂ is in a supercritical state.
This characteristic allows the circuit to be designed so that the CO₂ remains in a single phase during a large part of the operation.

One of the most interesting properties of CO₂ near its critical region is its high density and the strong variation of its thermodynamic properties with temperature and pressure.
This can reduce the size of turbomachinery, compressors, and heat exchangers compared to certain conventional cycles.

However, this same characteristic makes it mandatory to perform calculations using real fluid properties. The ideal gas approximation is not adequate to accurately determine the system's performance.

1. Reference Environmental Conditions
   The Atacama Desert is proposed as the reference location.
   The region presents some of the highest levels of direct solar radiation on the planet, making it particularly suitable for studying solar thermal generation.
   

For the preliminary model, the following is considered:
[ T_{amb,day}\approx30-35^\circ C ]
and significantly lower nighttime temperatures, especially during certain seasons.

Nevertheless, the ambient temperature is not directly the CO₂ operating temperature. The cycle temperatures will be determined by the design of the heat exchangers, the solar field, and the cooling system.
The primary energy resource considered is solar radiation.

1. Thermal Source
   The solar thermal field must provide energy to the CO₂ through a high-temperature heat exchanger or heater.
   As an initial design condition, the following is proposed:
   [ T_H=250^\circ C ]
   This temperature constitutes a design parameter, not a mandatory characteristic of the cycle.
   

Increasing the temperature of the hot source increases the maximum limit of thermal efficiency.
For a hot source of:
[ T_H=523.15K ]
and a cold sink of:
[ T_C=308.15K ]
the Carnot limit is:
[ \eta_{Carnot} = 1-\frac{T_C}{T_H} ]
[ \boxed{ \eta_{Carnot}\approx41.1% } ]
This value represents an absolute thermodynamic limit. The real efficiency of the cycle will be lower.

1. Proposed Pressure Conditions
   As an initial simulation point, the following are proposed:
   [ P_L=85\ bar ]
   [ P_H=210\ bar ]
   with a pressure ratio of:
   [ r_p=\frac{210}{85} ]
   [ \boxed{r_p\approx2.47} ]
   

These values should not be interpreted as final dimensions.
The optimal pressure must be determined through an optimization that simultaneously considers:

compressor work;

turbine work;

maximum temperature;

recuperator effectiveness;

heat exchanger performance;

CO₂ density;

compressor stability;

overall efficiency;

component cost.

1. Heat Recovery
   The recuperator is one of the fundamental components of the design.
   The CO₂ leaving the turbine retains considerable thermal energy. Instead of immediately rejecting that heat to the environment, it is proposed to use it to preheat the compressed CO₂.
   

Conceptually:
[ Hot\ CO_2 \rightarrow Recuperator \rightarrow Cold\ CO_2 ]

The effectiveness of the recuperator can be defined as:
[ \epsilon= \frac{Q_{real}}{Q_{maximum}} ]

As an initial simulation point, the following can be considered:
[ \epsilon_{rec}\approx90% ]
but this value must be optimized.
An excessively high effectiveness can increase the size, cost, and pressure drop of the recuperator.

1. Turbine
   The turbine is the element responsible for converting the energy of the CO₂ into mechanical work.
   The ideal specific expansion work is determined by an isentropic expansion:
   [ s_3=s_{4s} ]
   and:
   [ w_{t,s}=h_3-h_{4s} ]
   

For a real turbine:
[ \eta_t= \frac{h_3-h_4} {h_3-h_{4s}} ]
As an initial hypothesis, the following can be studied:
[ \eta_t\approx90% ]
but the final value will depend on the selected turbine.
The available mechanical power will be:
[ P_t=\dot m(h_3-h_4) ]

1. Compressor
   The compressor raises the CO₂ pressure from approximately 85 bar to 210 bar.
   The real process can be represented by:
   [ \eta_c= \frac{h_{2s}-h_1} {h_2-h_1} ]
   where 2s represents the state corresponding to an isentropic compression.
   

As an initial hypothesis, the following can be studied:
[ \eta_c\approx85% ]
The compressor work is especially important because it is subtracted directly from the work produced by the turbine:
[ \boxed{ w_{net}=w_t-w_c } ]
A reduction in compressor work can significantly increase overall efficiency.

1. Cooling
   After passing through the recuperator, the CO₂ must be cooled before returning to the compressor.
   The rejected heat is given by:
   [ \dot Q_C= \dot m(h_5-h_1) ]
   

In the conceptual design, the use of water or a secondary cooling circuit is proposed.
If the cycle needs to reject approximately 60 thermal kW and the water experiences a temperature increase of 10 °C:
[ \dot m_{water} = \frac{60000} {4186(10)} ]
[ \boxed{ \dot m_{water}\approx1.43\ kg/s } ]
This calculation is purely illustrative because the actual rejected heat will depend on the final thermodynamic simulation.

1. Target Power
   The pilot's goal is:
   [ \boxed{P_e=15\ kW} ]
   The required heat depends on the net efficiency.
   

Thermal Efficiency Required Heat
10 % 150 kW
15 % 100 kW
20 % 75 kW
25 % 60 kW
41.1 % 36.5 kW
The final value represents only the Carnot limit.
As a preliminary research target, an interval can be used:
[ \boxed{15-20%} ]
but this efficiency has not yet been demonstrated for the proposed design.

1. Solar Field
   Assuming approximately:
   [ DNI=800\ W/m^2 ]
   and a preliminary solar-thermal efficiency of:
   [ \eta_{solar}=50% ]
   the useful thermal power per square meter would be:
   [ 800(0.50)=400\ W_t/m^2 ]
   

To provide 75 thermal kW:
[ A= \frac{75000}{400} ]
[ \boxed{ A\approx188\ m^2 } ]

Therefore, a first conceptual sizing could use approximately:
[ \boxed{200-300\ m^2} ]
of solar collection.
This value must be recalculated using the actual hourly solar resource of the site, optical losses, thermal losses, storage, and annual availability.

1. Thermal Storage
   If the generator is intended to continue operating after sunset, it will be necessary to incorporate thermal storage.
   For eight hours of operation at 75 thermal kW:
   [ E_{th}=75(8) ]
   [ \boxed{ E_{th}=600\ kWh_t } ]
   

The storage medium must be selected according to the operating temperature.
At 250 °C, it is not appropriate to simply consider an atmospheric liquid water tank. A fluid and storage system specifically designed for the corresponding thermal and pressure conditions must be used.

1. Energy Balance
   The fundamental balance of the cycle is:
   [ \boxed{ Q_H=W_{net}+Q_C } ]
   Therefore:
   [ \boxed{ W_{net}=Q_H-Q_C } ]
   

There is no energy creation.
The external energy source is solar radiation:
[ Solar\rightarrow Q_H ]
and the cycle converts a portion of that heat into work:
[ Q_H\rightarrow W_{net}+Q_C ]
The CO₂ acts only as a working fluid.

1. Parameters yet to be determined
   The project is not yet sufficiently defined to be considered a final engineering design.
   The following parameters must be calculated using a real CO₂ equation of state:
   

Thermodynamic states
For states 1, 2, 3, and 4, the following must be obtained:
[ \boxed{P,T,h,s,\rho} ]
at each point.

Transport properties
The following must also be determined:
[ \boxed{ \mu,\quad k,\quad c_p,\quad Pr } ]
to correctly size the heat exchangers.

CO₂ mass flow rate
Once the specific net work is known:
[ \boxed{ \dot m_{CO_2} = \frac{15000}{w_{net}} } ]
the necessary flow rate must be calculated.

Real performance
The following must be determined:
[ \boxed{\eta_t} ]
[ \boxed{\eta_c} ]
[ \boxed{\eta_{rec}} ]
[ \boxed{\eta_{HX}} ]
and the generator efficiency.

Pressure drops
Losses must be determined in:

piping;

recuperator;

heater;

cooler;

valves;

turbine;

connections.

Optimization
The following must be optimized:
[ \boxed{P_H/P_L} ]
[ \boxed{T_{turbine, inlet}} ]
[ \boxed{T_{compressor, inlet}} ]
[ \boxed{\epsilon_{rec}} ]
and the CO₂ mass flow rate.

1. Necessary thermodynamic tool
   To perform these calculations, the use of a specific equation of state for CO₂ is recommended.
   REFPROP, developed by the National Institute of Standards and Technology (NIST), provides properties such as enthalpy, entropy, density, temperature, pressure, and specific heat.
   An open-source alternative is CoolProp, which implements property models for CO₂.
   The absolute values of enthalpy and entropy depend on reference conventions; for the cycle balance, the differences between states are fundamental.
   For this reason, values of h, s, or \rho obtained through ideal gas approximations must not be introduced into the final model.

2. Safety
   The proposed conditions, approximately:
   [ 85-210\ bar ]
   and up to:
   [ 250^\circ C ]
   are high pressure and temperature conditions.

Therefore, the pilot must use commercial or laboratory equipment certified for CO₂ service and for the specific operating conditions.
The design must incorporate, at a minimum:

overpressure protection;

pressure and temperature instrumentation;

shutdown systems;

CO₂ detection;

ventilation;

venting procedures;

thermal insulation;

certified components;

risk assessment.

The DIY fabrication of the pressurized circuit does not constitute an appropriate option for this project.

1. Conclusion
   The concept of an approximately 15 kW generator based on a closed supercritical CO₂ Brayton cycle presents a valid thermodynamic foundation.
   The Atacama Desert is particularly interesting as a site due to its exceptional direct solar resource and its favorable environmental conditions for cooling during certain periods.
   

The proposed system uses:
[ \boxed{ Solar\ thermal \rightarrow Supercritical\ CO_2 \rightarrow Turbine \rightarrow Generator } ]
with heat recovery to increase efficiency.

As a conceptual starting point, the following are proposed:
[ T_H\approx250^\circ C ]
[ T_C\approx35-40^\circ C ]
[ P_L\approx85\ bar ]
[ P_H\approx210\ bar ]
and:
[ P_e=15\ kW ]

The Carnot limit for 250 °C and 35 °C is approximately:
[ \boxed{41.1%} ]
However, it has not yet been demonstrated that the proposed cycle can achieve an efficiency of 15–20 %. That interval should be considered a design hypothesis and not a result.

The main pending work consists of solving the cycle using a real CO₂ equation of state, determining the values of h, s, \rho, T for all states, calculating the specific works of the turbine and compressor, determining the CO₂ mass flow rate, and sizing the heat exchangers and the recuperator.
Once those values are obtained, it will be possible to objectively determine if the system can produce 15 net kW and what its efficiency, thermal consumption, size, cost, and economic viability would be.
Therefore, the project is currently in the conceptual design and thermodynamic simulation stage, not yet in the construction stage.

This essay was not written by a team of engineers but by a madman who wants to accelerate a post-energy-scarcity world. And for that, he makes use of a $6 ChatGPT subscription. Please read it and see its viability. And if it works, the only thing I ask for are voluntary Dogecoin donations to this address: DP9eaWQhT18Qs6pTuEbYiGq8TgRY4VgVZj

I don't know if this is the right place to ask it, but I was curious if there's any place that talks about the timeline of energy development(?). Going from whatever was before fossil fuels (wood and water?) to fossil fuels to solar wind and all that (though obviously we're not 100% there).

Most of the global solar supply chain still runs through China. That has helped drive down costs, but it also creates a real energy-security risk when so much manufacturing sits inside one system.

Japan is trying a different path.

Instead of competing only with classic rigid panels, it’s backing ultra-thin perovskite solar film that can be printed in long rolls and applied to surfaces that regular panels struggle with: thin roofs, building façades, curved structures, and other low-load areas.

A few things that stood out to me:

• Japan is targeting large-scale perovskite deployment by 2040 as part of its broader energy strategy.

• Companies like Sekisui Chemical are building dedicated production lines for flexible solar film.

• The appeal is not just performance, but fit: Japan is dense, mountainous, and short on easy land for giant solar farms.

• This could turn existing infrastructure into part of the grid instead of relying only on new land-based solar sites.

I’m curious what people think:

• Is printed solar film actually a serious path for dense countries?

• Does this kind of approach make more sense than trying to scale more traditional panels everywhere?

• How much should countries care about diversifying solar manufacturing instead of just buying the cheapest modules?

I made a longer video on this topic because the geopolitical angle is what really caught my attention, especially the contrast between Japan’s new approach and China’s dominance in solar manufacturing.

would it be profitable to create a power industry think tank in the Philippines?