1. A power-distribution-system management apparatus
comprising:
an acquiring unit to acquire an amount of insolation, which is a measurement value measured by a pyranometer, via a smart meter network, which is a network used to collect a measurement value of a smart meter that measures an amount of electric power; and
a power-generation-amount estimating unit to estimate, on the basis of the amount of insolation, a power generation amount of each of two or more solar power generation facilities connected to a power distribution line of a high voltage system.
2. The power-distribution-system management apparatus
according to claim 1, wherein
the acquiring unit further acquires, via the smart meter network, a measurement value of an all-quantity buyback smart meter, which is a smart meter that measures a power generation amount of an all-quantity-buyback solar power generation facility that is a subject of an all-quantity buyback contract among the two or more solar power generation facilities connected to the power distribution line, and
the power-generation-amount estimating unit estimates, on the basis of the amount of insolation and the measurement value of the all-quantity buyback smart meter, the power generation amount of each of the solar power generation facilities connected to the power distribution line.
3. The power-distribution-system management apparatus

according to claim 2, wherein
a setting position of the all-quantity-buyback solar power generation facility connected to the all-quantity buyback smart meter and a setting position of the pyranometer are set as measurement points, and
the power-generation-amount estimating unit estimates the power generation amount of the solar power generation facility on the basis of measurement values of a trio of the measurement points selected in ascending order of distances from the solar power generation facilities.
4. The power-distribution-system management apparatus
according to claim 1, 2, or 3 comprising:
a total-power-generation-amount calculating unit to estimate a total solar power generation amount, which is a sum of power generation amounts by the solar power generation facilities connected to the power distribution line; and
a total-load calculating unit to estimate a total load amount connected to the power distribution line on the basis of the total solar power generation amount and a tidal current measured at an end point on an upstream side of the power distribution line.
5. The power-distribution-system management apparatus according to claim 4, further comprising a load calculating unit to calculate a total load amount of a day on the basis of the total load amount in past.
6. The power-distribution-system management apparatus according to claim 5, comprising a voltage control unit to determine, on the basis of the total load amount of the day, a control amount of a voltage control device connected to

the power distribution line.
7. The power-distribution-system management apparatus according to any one of claims 1 to 6, wherein the power-generation-amount estimating unit multiplies the amount of insolation by a coefficient for converting the amount of insolation into a power generation efficiency to thereby calculate the power generation efficiency, estimates a power generation amount of the solar power generation facility, which is an estimation target of a power generation amount, on the basis of the power generation efficiency, and, when determining on the basis of the amount of insolation in past under a same condition that the pyranometer, which has measured the amount of insolation, is deteriorated, changes the coefficient by which the amount of insolation corresponding to the pyranometer is multiplied.
8. The power-distribution-system management apparatus according to any one of claims 1 to 7, wherein the pyranometer is set in an electric pole.
9. The power-distribution-system management apparatus according to any one of claims 1 to 8, wherein the pyranometer is set in a relay tower of a mobile communication system.
10. A power-distribution-system management system comprising:
a power distribution line of a high voltage system; a plurality of solar power generation facilities connected to the power distribution line;
a smart meter network, which is a network used to

collect a measurement value of a smart meter that measures
electric energy;
a pyranometer to measure an amount of insolation; and a power-distribution-system management apparatus,
wherein
the power-distribution-system management apparatus
includes:
an acquiring unit to acquire the amount of
insolation via the smart meter network; and
a power-generation-amount estimating unit to
estimate, on the basis of the amount of insolation, a power
generation amount of each of the solar power generation
facilities.
11. A power-generation-amount estimating method comprising:
a first step of acquiring an amount of insolation, which is a measurement value obtained by measurement of a pyranometer, via a smart meter network, which is a network used to collect a measurement value of a smart meter that measures an amount of electric power; and
a second step of estimating, on the basis of the amount of insolation, a power generation amount of each of two or more solar power generation facilities connected to a power distribution line of a high voltage system.