1. NanoGrids for Home Application in a Power Cloud Framework
 D. Menniti, A. Pinnarelli, N. Sorrentino, A. Burgio, G. Brusco, V. Frascà, L. Mendicino, and M. Mercuri
Department of Mechanical, Energy and Management Engineering (DIMEG) University of Calabria Via Bucci 42C, Arcavacata di Rende - CS, Italy

2. Summary
The paper shows the higher economic benefit a prosumer may reach when he adopts a nanogrid in a Power Cloud framework instead of in a stand alone framework.

3. A nanogrid for home application
Nanogrids are small dc microgrids (generally not over 5 kW) which typically serve a single building or a single home. The nanogrid interconnects generation units and plants (PV, micro-CHP Stirling-engine, gas micro-turbines, fuel cells, etc.) and electric storage systems. Micro-sources, storage systems and loads are connected to a common dc bus through appropriate power converters.
The Power Electronic Interface (PEI) is a bidirectional power converter that regulates the power flow between the nanogrid and the grid. The PEI allows the nanogrid to operate as a single system, providing ancillary services to the grid. IEC communication is available.

4. Power Cloud as a model
Power Cloud is a management and business model applicable to the Integrated Community Energy Systems (ICESs) that is locally and collectively organized energy systems.
Power Cloud is a feasible solution for put in practice the concept of sustainable energy communities, community energy systems, micro-grids community, and peer-to-peer energy.

5. Urban and rural area
A PV system on the rooftop is an easy and cost-effective way to independently fulfil a part of own electricity demand, reduce the electric bill, generate savings, contribute to the exploitation of renewable energy sources, and contribute to the environmental preservation by reducing the greenhouse gas emissions. Such an opportunity is evidently reserved to those users which have ample space for installing a PV system; on the contrary, it is denied to those users which, as an example, live in apartment building.
Local demand
Remote demand
Local demand
Remote demand

6. Power Cloud for social development
Citizens in urban area and those in rural area are joined in a process of social development where exploiting RESs and self-consumption are two main pillars.
Citizens in rural area, which have large area, oversize their PV plants so to generate electricity for those living in the downtown and which cannot install a PV plant on rooftop.
Citizens may produce energy and participate in the electricity market, selling energy to the formers. The electricity market is accessible to all citizens that become real market operators in aggregate form. Such a transformation would have an immediate economic return, relying on price margins that exist between the wholesale and retail prices.

7. Members of Power Cloud Members are:
Simple Generation Systems Power Cloud Consumers Power Cloud Prosumers
Members are managed by the aggregator, i.e. Community Energy Provider (CEP), which is a no-profit entity which legally represents the community. The CEP is the power dispatcher. The CEP interfaces the Power Cloud and the market /system operators. The CEP ensures the functionalities of the whole system.

8. Simple generation systems
Simulating the Power Cloud
Numerical experiment were carried out so to calculate a feasible Power Cloud. Below four fundamental rules which have been adopted for simulating power cloud.
The electricity not self-consumed by prosumers is given to power cloud for free (export price is zero);
The cost-free electricity provided by prosumers is sold to consumers at a discounted price (25% less than the PE i.e. price suggested by the authority each 3 months )
The cost-free electricity provided by prosumers and not sold to consumers is sold to the wholesale market (zonal price);
The electricity price paid to simple generation systems is 5% higher than the zonal price;
The electricity cost for the prosumers is the PE.
Prosumers
Consumers
Simple generation systems

9. The consumer/prosumer type
A consumer
3kW contractual power
5621 kWh/year
A prosumer
3kW contractual power
5621 kWh/year
3kWp PV plant,
1400 €/kWp
PV plant placed in Southern Italy (PVGIS)
3kW-3kWh EESS, DOD_lead 50%, DOD_lithium 30%, RTE 80%, tax deduction equal to 50% of the investment costs spread over 10 years
How much it costs????
5kW nanogrid, …….

10. Nanogrid cost: a prototype
A 3.3kW prototype of a 3-phases nanogrid has been designed and built in the laboratory of Electric Power Systems and Renewable Energy Sources (LASEER).
The prototype to implements the innovative business/management model of Power Cloud. The prototype is able to move the user from “Consumer” to “Prosumer”, from “business as usual” to “power cloud”. For the real time control, the prototype adopts the dc bus signalling (DBS) control strategy. The DBS control strategy has been implemented in a prioritized fashion so to maximize the use of renewables and to maximize self-consumption.

11. The consumer/prosumer type
A consumer
3kW contractual power
5621 kWh/year
A prosumer
3kW contractual power
5621 kWh/year
3kWp PV plant,
1400 €/kWp
PV plant placed in Southern Italy (PVGIS)
3kW-3kWh EESS, DOD_lead 50%, DOD_lithium 30%, RTE 80%, tax deduction equal to 50% of the investment costs spread over 10 years
5kW nanogrid, 4300€_lead, 5000€_lithium

12. Two alternative frameworks
1) Can you go into debts? 1 2 3 No
Yes ??
2) Are you a credit worthy customer?
3) Will your income be so high in the next 10 years to release off tax deduction?
Stand Alone Framework
Power Cloud Framework
Contact the Power Cloud;
Adhere to Power cloud;
Enjoy the installation of your PV, EESS, Nanogrid;
Pay preferential tariff for electricity bill and installment;
Do not release any Tax deduction;
Export your electricity at 0 €/MWh.
Go to Bank and ask for a loan (9 %, 20 years);
Complete administrative procedures;
Install PV, EESS, Nanogrid;
Pay bill and installment;
Release Tax deduction for 10 Years;
Export your electricity at 39 €/MWh.

13. Stand alone framework Time interval Cost/year [€] Cost [€] Saving [€]
Business as usual
0-20
1392,67
27853,40
0,00
Lead EESS without tax deduction
0-10
1773,60
22546,00
5307,40
10-20
481,60
Lead EESS with tax deduction *
1348,69
18296,90
9556,50
Lithium EESS without tax deduction
1829,9
22618,50
5234,90
431,95
Lithium EESS with tax deduction *
1369,95
18019,00
9834,40
Choice 0
Choice 1
Choice 2
Choice 3
Choice 4
* tax deduction equal to 50% of the investment costs spread over 10 years.

14. Lithium EESS with deduction Lithium EESS without deduction
Stand alone and Power cloud framework
Time interval
Cost/year [€]
Cost [€]
Saving [€]
Bussiness as usual
0-20
1392,67
27853,40
0,00
Lithium EESS with deduction
0-10
1369,95
18019,00
9834,40
10-20
431,95
Lithium EESS without deduction
0-10
1323,00
17958,20
9895,20
10-20
472,82
For all those users which cannot chose the stand alone framework Power cloud allows them to achieve almost equal saving. Cost/Year is obtained as sum of:
(EG) (Tax) (Inst) (Deduc.) (ExP)
Bussiness as usual: 1392,67 = , ,20
Stand alone: ,95 = , , ,50 – 460,00 – 41,35
Power Cloud: ,00 = , , ,20 – 0,00 – 0,00
Installment in Power Cloud reduces because 1) the price for a nanogrid reduces from 5000 € to 3000 € due to economies of scale 2) the loan lenght reduces from 9% to 2% when Power Cloud is put in practice by Public Administration.

15. A feasible Power cloud
A feasible Power Cloud as 4037 members. Among members, 1011 of them have not a nanogrid, any PV plant, any EESS; they buy electricity from Power Cloud and benefit of a discount of 25% on electricity price. Among them, 3025 of them have a nanogrid, a PV plant and an EESS; they buy and sell electricity inside the power cloud to members and outside to the whosale market. It remains 1 member with an equivalent 9 MW PV plant.
Why a Power Cloud of 4037 members?
The Power Cloud is a no-profit organization. A Power Cloud of 4037 members has costs; these costs are estimated being € (about 75 € member/year.
Gestore dei Mercati Energetici (GME): costs due to the access for the exchange energy platform and energy trading fees; b) Terna (TSO): costs due to guarantees, dispatching and real time power imbalances; c) Distribution System Operator (DSO): energy transport and system charges; d) Agenzia delle Dogane e Monopoli (ADeM): excise duty; e) Aggregator: daily operations of PC management such as the billing system, measurement, software, personnel and general expenses.
A Power Cloud of 4037 members has revenues from the energy sale to the 1011 users and to the whosale market; these revenues are € and they balance the costs.

16. Conclusion
The paper demonstrated the higher economic benefit a prosumer may reach when he adopts a nanogrid in a Power Cloud framework instead of in a stand alone framework.
A Power Cloud framework also:
allows a wider spread of electricity storage systems – so to maximize the self consumption – preventing incentive policies from Governments.
A Power Cloud also favorites:
the exploitation of renewables sources;
the economic growth of less-affluent Regions;
the participation and the involvement of citizens;
the reinforcement of schemes of mutual support.

17. Thank you for your attention
 D. Menniti, A. Pinnarelli, N. Sorrentino, A. Burgio, G. Brusco, V. Frascà, L. Mendicino, and M. Mercuri
Department of Mechanical, Energy and Management Engineering (DIMEG) University of Calabria Via Bucci 42C, Arcavacata di Rende - CS, Italy